There is one thing common in the IBM products: they don't like any regional settings other than US :S
For instance, you are trying to record a Web application with IBM Rational Functional Tester. During the recording, you press the Pause or Stop button and get the warning that "... the record activity can not be started / stopped ...".
Change the regional settings to US (and language to English) and try again.
[ I wasted a whole work-day just because of this easy(!) configuration problem ! ]