All Blocks in One Theme Automatically Disabled On a Drupal 7 site that I help maintain, the blocks in one of the themes were all disabled automatically.  I manually added all of the blocks back of course, but can't promise this won't happen again.  To try to find out what happened, I queried the block table and discovered that the tracking columns are not provided (e.g. created, changed, uid).  So then I went on to see if MySQL could tell me the last time that these rows were modified, but there is no such native function.

Has anyone seen this problem?
I haven't run into this specific problem, but I would advise getting as much of this as you can into Features - that way you can easily revert it all back, should this problem recur, and you wouldn't have to do it manually.