Encountering problems with PUM?
First off, be sure that
--you are using the Change Assistant and Tools codeline delivered in the Image you are using. Why? Many times there are hot fixes included there, which were not included in the GA.
--you have checked the PUM Home Page, doc id 1641843.2, tab section (at top) Known Issues. There are known issues posted there for 'general' as well as for application specific images.