scala plugin problems when play2 plugin active

Hi,

I'm using Intellij 12.1.6 with the scala and play2 plugins, version 0.22.302. Lately I'm getting fuzzy problems, like only very limited syntax highlighting, some references can't be resolved. Sometimes the editor doesn't work at all, but only for scala files. All this disappears when I deactivate the play2 plugin. I've already reinstalled Intellij and cleared all caches.
Does anybody have the same problems?

thanks
Simon