This problem is not that the form hangs - it's because the finish button doesn't gets clicked. This is an issue with Ubuntu 9.10 and Eclipse 3.5 (Zend studio is based on Eclipse).
The simple solution is to use the spacebar to press those buttons (the "New Project" Finish button isn't the only one).
However - there is a solution here: http://blog.export.be/2009/10/fixing-eclipse-for-ubuntu-karmic-koala-9-10/