TYPO3 Core

NEW Installation dummy in one location source in another location. Both foldernames are renamed. dummy to "001" source to "0t3s" (perhaps thats important!
All symlinks are working fine and are installed like Michael Stucki wrote in install.txt
User and Owner rights / permissions are also set like described in this file.
As we wanted to update also thos sysext (rtehtml) and install ext. globally we changed also here the rights / permissions like described for the dummy subfolder typo3conf
Install Tool is loading fine. We reduced everything to an absolut minimum. Only Database was input. And then reloaded.
Then the error came that sv is missing. As written in other threads we deleted $TYPO3_CONF_VARS['EXT']['requiredExt'] = 'cms,version,lang,sv'; and also temp files.

Everything was working until we installed ANY extension in global. Then the error occured. main(../../../init.php): failed to open stream: No such file or directory in ... Extension path
We tried it about 7 times and it is reproducable.

Copying a new localconf.php file in the typo3conf folders AND changing the rights to USER:NOBODY (nobody=server) let the install-tool start again. (before it was Username:Username (groupname=username)
As soon as we install an extension like t3quixplorer or templaVoila globally we receive the init error. The same extensions installed locally works fine!

CONST: php_sapi_name: apache
OTHER: TYPO3_VERSION: 4.0.1
OTHER: PHP_VERSION : 4.4.2
We tried with and without realUrl and with and without .htaccess but no changes
We can't install extensions globally so that there isn't this init.php error.
(issue imported from #M4117)