Index: t3lib/class.t3lib_extmgm.php
===================================================================
--- t3lib/class.t3lib_extmgm.php	(revision 10289)
+++ t3lib/class.t3lib_extmgm.php	(revision )
@@ -312,8 +312,8 @@
 						$positionArray = t3lib_div::trimExplode(':', $position);
 						if ($positionArray[0] == 'replace') {
 							foreach ($GLOBALS['TCA'][$table]['palettes'] as $palette => $paletteDetails) {
-								if (preg_match('/\b' . $palette . '\b/', $typeDetails['showitem']) > 0
-										&& preg_match('/\b' . $positionArray[1] . '\b/', $paletteDetails['showitem']) > 0) {
+								if (preg_match('/\b' . $positionArray[1] . '\b/', $paletteDetails['showitem']) > 0
+										&& preg_match('/\b' . $palette . '\b/', $typeDetails['showitem']) > 0) {
 									self::addFieldsToPalette($table, $palette, $str, $position);
 									$fieldExists = TRUE;
 								}
@@ -323,8 +323,8 @@
 								$fieldExists = TRUE;
 							} else {
 								foreach ($GLOBALS['TCA'][$table]['palettes'] as $palette => $paletteDetails) {
-									if (preg_match('/\b' . $palette . '\b/', $typeDetails['showitem']) > 0
-									&& preg_match('/\b' . $positionArray[1] . '\b/', $paletteDetails['showitem']) > 0) {
+									if (preg_match('/\b' . $positionArray[1] . '\b/', $paletteDetails['showitem']) > 0
+											&& preg_match('/\b' . $palette . '\b/', $typeDetails['showitem']) > 0) {
 										$position = $positionArray[0] . ':--palette--;;' . $palette;
 									}
 								}
@@ -335,8 +335,8 @@
 							$fieldExists = TRUE;
 						} else if(is_array($GLOBALS['TCA'][$table]['palettes'])) {
 							foreach ($GLOBALS['TCA'][$table]['palettes'] as $palette => $paletteDetails) {
-								if (preg_match('/\b' . $palette . '\b/', $typeDetails['showitem']) > 0
-								&& strpos($paletteDetails['showitem'], $str) !== FALSE) {
+								if (strpos($paletteDetails['showitem'], $str) !== FALSE
+								&& preg_match('/\b' . $palette . '\b/', $typeDetails['showitem']) > 0) {
 									$fieldExists = TRUE;
 								}
 							}
@@ -433,10 +433,12 @@
 				);
 				// If it's a new palette, just set the data:
 			} else {
+				if($addFields) {
-				$paletteData['showitem'] = self::removeDuplicatesForInsertion($addFields);
-			}
-		}
-	}
+					$paletteData['showitem'] = self::removeDuplicatesForInsertion($addFields);
+				}
+			}
+		}
+	}
 
 	/**
 	 * Adds a list of new fields to the TYPO3 USER SETTINGS configuration "showitem" list, the array with
@@ -472,7 +474,10 @@
 	 */
 	protected static function executePositionedStringInsertion($list, $insertionList, $insertionPosition = '') {
 		$list = trim($list);
+
+		if($insertionList) {
-		$insertionList = self::removeDuplicatesForInsertion($insertionList, $list);
+			$insertionList = self::removeDuplicatesForInsertion($insertionList, $list);
+		}
 
 		if ($insertionList) {
 				// Append data to the end (default):
@@ -480,15 +485,14 @@
 				$list .= ($list ? ', ' : '') . $insertionList;
 				// Insert data before or after insertion points:
 			} else {
-				$positions = t3lib_div::trimExplode(',', $insertionPosition, TRUE);
 				$items = self::explodeItemList($list);
 				$isInserted = FALSE;
-					// Iterate through all fields an check whether it's possible to inserte there:
+					// Iterate through all fields and check whether it's possible to insert there:
 				foreach ($items as $item => &$itemDetails) {
 					$needles = self::getInsertionNeedles($item, $itemDetails['details']);
 						// Insert data before:
 					foreach ($needles['before'] as $needle) {
-						if (in_array($needle, $positions)) {
+						if (strpos($needle, $insertionPosition) !== FALSE) {
 							$itemDetails['rawData'] = $insertionList . ', ' . $itemDetails['rawData'];
 							$isInserted = TRUE;
 							break;
@@ -496,7 +500,7 @@
 					}
 						// Insert data after:
 					foreach ($needles['after'] as $needle) {
-						if (in_array($needle, $positions)) {
+						if (strpos($needle, $insertionPosition) !== FALSE) {
 							$itemDetails['rawData'] .= ', ' . $insertionList;
 							$isInserted = TRUE;
 							break;
@@ -504,7 +508,7 @@
 					}
 						// Replace with data:
 					foreach ($needles['replace'] as $needle) {
-						if (in_array($needle, $positions)) {
+						if (strpos($needle, $insertionPosition) !== FALSE) {
 							$itemDetails['rawData'] = $insertionList;
 							$isInserted = TRUE;
 							break;
@@ -550,23 +554,18 @@
 		}
 
 		if ($insertionList && preg_match_all($pattern, $insertionList, $insertionListMatches)) {
-			$insertionItems = array();
-			$insertionDuplicates = FALSE;
-
-			foreach ($insertionListMatches[2] as $insertionIndex => $insertionItem) {
-				if (!isset($insertionItems[$insertionItem]) && !in_array($insertionItem, $listItems)) {
-					$insertionItems[$insertionItem] = TRUE;
+			$insertionList = '';
+			$insertionListMatches[2] = array_flip(array_flip($insertionListMatches[2]));
+			$listItems = array_diff($insertionListMatches[2], $listItems);
+			if (count($listItems) > 0) {
+				$insertionListMatches[2] = array_intersect_key($listItems, $insertionListMatches[0]);
-				} else {
+			} else {
-					unset($insertionListMatches[0][$insertionIndex]);
-					$insertionDuplicates = TRUE;
+				$insertionListMatches[2] = $insertionListMatches[0];
-				}
+			}
+			if (count($insertionListMatches[2]) > 0) {
+				$insertionList = implode(',',$insertionListMatches[2]);
 			}
-
-			if ($insertionDuplicates) {
-				$insertionList = implode('', $insertionListMatches[0]);
-			}
+		}
-		}
-
 		return $insertionList;
 	}
 
@@ -580,9 +579,10 @@
 	 * @return	array		The needled to be used for inserting content before or after existing fields/items
 	 */
 	protected static function getInsertionNeedles($item, array $itemDetails) {
-		if (strstr($item, '--')) {
+
-				// If $item is a separator (--div--) or palette (--palette--) then it may have been appended by a unique number. This must be stripped away here.
+		// If $item is a separator (--div--) or palette (--palette--) then it may have been appended by a unique number. This must be stripped away here.
-			$item = preg_replace('/[0-9]+$/', '', $item);
+		if ($item{0} === '-') {
+			$item = rtrim($item, '0123456789');
 		}
 
 		$needles = array(
@@ -616,7 +616,7 @@
 		foreach ($itemParts as $itemPart) {
 			$itemDetails = t3lib_div::trimExplode(';', $itemPart, FALSE, 5);
 			$key = $itemDetails[0];
-			if (strstr($key, '--')) {
+			if ($key{0} === '-') {
 					// If $key is a separator (--div--) or palette (--palette--) then it will be appended by a unique number. This must be removed again when using this value!
 				$key .= count($items);
 			}
@@ -651,9 +651,10 @@
 		$itemParts = array();
 
 		foreach ($items as $item => $itemDetails) {
-			if (strstr($item, '--')) {
+
-					// If $item is a separator (--div--) or palette (--palette--) then it may have been appended by a unique number. This must be stripped away here.
+			// If $item is a separator (--div--) or palette (--palette--) then it may have been appended by a unique number. This must be stripped away here.
-				$item = preg_replace('/[0-9]+$/', '', $item);
+			if ($item{0} === '-') {
+				$item = rtrim($item, '0123456789');
 			}
 
 			if ($useRawData) {