Hi guys,
This is the worst kind of problem there is... not being able to provide detailed steps that reproduce it, preferably every time.
There have been issues reported in the past that might be something in this direction, and may even well be a part of this problem, but many of them have been closed, as there is no way for the developer to reproduce it. I would gladly write an issue for you if I thought this would add something to what has allready been written... but when we don't quite manage to get our fingers on it, then it's difficult.
My opinion, and my advice, is that we all watch out for patterns that we might spot that will reproduce this problem. Something like I finally (with help from the community) wrote down inside this issue here. If you find something reproducable, please let us know.
Generally about this problem, it may even be the same one as in the issue I referenced, so this might get fixed when that gets fixed.
Palli