i´ve created a ticket on the 15. dec 2009 about this problem ...
The latest response from Roman (02.APR.2010 16:47 (GMT) ):
The problem seems to be fixed in the next version of Zend Studio. This release is currently in final QA stages and should be made generally available fairly soon.
now i´m waiting for the "next version"
but you are right, the communication from zend to their customers are incredible poor.