As reported before (http://www.igniterealtime.org/community/thread/35411?tstart=0) the Beta 2 has some serious issues with handling roster entries that belong to an empty group. We have done some analysis on that and provided a patch to winsrev.
Subsequent testing of a patched version of 2.6.0b2 showed additional errors. Specifically, the update of the presence status of the user with <-/group> is failing. We also see a dependency of the error decribed in the posting above on the presence status of the user (e.g. donald.duck).
According to the SVN we had several changes on the contact list. I would suggest to back them out of the current trunk and give them an additional review.
Any opinion on that?