I just fixed some weird behaviour with one of my plug-ins that depend from another one since it uses some extension point. The message was that the extension point in the plugin could not be found. After some search on the net I stumbled upon the Eclipse Wiki Book. All the tips mentioned there did not help. What I noticed though was a bunch of access rules. Among them the following: forbidden */**. So I compared the Manifest file with other plug-ins there I noticed the one with the problem had an entry „Eclipse-Buddy: global“. Removing this line got me rid of the access rules and my problem.
Since all other plug-ins are based on 3.2 and only this on 3.4 I figure that might be the problem.