TYPO3 Core

Flexform configuration (working)

<settings.image>
                        <TCEforms>
                            <label>
                                LLL:EXT:seam_template/Resources/Private/Language/locallang_db.xlf:plugins.ulme.image
                            </label>
                            <config>
                                <type>inline</type>
                                <minitems>1</minitems>
                                <maxitems>1</maxitems>
                                <foreign_table>sys_file_reference</foreign_table>
                                <foreign_table_field>tablenames</foreign_table_field>
                                <foreign_label>uid_local</foreign_label>
                                <foreign_sortby>sorting_foreign</foreign_sortby>
                                <foreign_field>uid_foreign</foreign_field>
                                <foreign_selector>uid_local</foreign_selector>
                                <appearance type="array">
                                    <createNewRelationLinkTitle>LLL:EXT:frontend/Resources/Private/Language/locallang_ttc.xlf:images.addFileReference</createNewRelationLinkTitle>
                                </appearance>
                            </config>
                        </TCEforms>
                    </settings.image>

Flexform configuration (not working):

<settings.image>
                        <TCEforms>
                            <label>
                                LLL:EXT:seam_template/Resources/Private/Language/locallang_db.xlf:plugins.ulme.image
                            </label>
                            <config>
                                <type>inline</type>
                                <minitems>1</minitems>
                                <maxitems>1</maxitems>
                                <foreign_table>sys_file_reference</foreign_table>
                                <foreign_table_field>tablenames</foreign_table_field>
                                <foreign_label>uid_local</foreign_label>
                                <foreign_sortby>sorting_foreign</foreign_sortby>
                                <foreign_field>uid_foreign</foreign_field>
                                <foreign_selector>uid_local</foreign_selector>
                                <appearance type="array">
                                    <createNewRelationLinkTitle>
LLL:EXT:frontend/Resources/Private/Language/locallang_ttc.xlf:images.addFileReference
</createNewRelationLinkTitle>
                                </appearance>
                            </config>
                        </TCEforms>
                    </settings.image>

The difference is that the value of "createNewRelationLinkTitle" is surrounded by breaks (or spaces) and therefore is not parsed correctly.
f.e. the "label" field works as exptected

maybe there are other cases where this doesnt work...

PS: didn't know which category i should put this bug, sorry for that.