Originally Posted by Perkin
No, Tablet was awake throughout, and no screen rotation (I kept it in portrait mode and didn't move the tablet to cause activity resetting). Sorry.
Well, I sort-of expected that. No reason why this should be easy.
I have changed CC and calibre to do deletes as one transaction instead of many, adding the progress dialog in the process. This removes that update you noticed. I haven't found a conclusive reason to believe that the update is the culprit, but it is useless work so removing it is good. As a side benefit, performance is much better. These changes should be available in Friday's calibre release (they aren't yet in "trunk"). I have also added several "defensive" changes to CC to check for things that should never happen. These also might fix it.
At this point I want to wait until Friday to see if the problem goes away.
Thank you (!) for reporting the problem and helping me (try to) find it.
Given that I cannot reproduce it, information like yours provides the only pointers I have toward whatever we might have done to create this problem.