[TYPO3-english] Icon styles missing

[Michael HüŸgelschŠaffer]

Hi there,

we got a wierd problem with backend styles for some extensions.
Sometimes the styles for extension datasets or pages containing an 
extension are not loaded so it only shows the fatal-error-icon in 
backend. A look in the files shows, that e.g. 
".t3-icon-pages-contains-news" is not available in the compressed file.
That happend for all classes that belong to "pages-contains"-styles and 
also for icons of datasets.
Here is a screenshot: 
http://www.mehrwert.de/fileadmin/screenshot/20110110_screenshot_missing_icons.png

TYPO3 is at version 4.4.6 (but also happend with version 4.4.4). I just 
changed the icon inclusion for tt_news to 
t3lib_SpriteManager::addTcaTypeIcon() instead of $ICON_TYPES['news'].

Anybody also has the same problem or got a clue where to search for the 
problem?