Same issue here. I can’t find the trigger either, it seems to be related to working within admin but I can’t be 100%. Today I was cleaning tags and verifying them. All went well when I noticed Akismet having a queue. I remove all of the spam and reload my site and viola, back to default.
Whatever is causing this toggle to default problem / behavior / issue you’d think would be rather obvious.
Last night it was occuring when I was working w/ the sidebar widgets but not every time, more like every 10th time. Just bizarre.
Any thoughts or advice would be welcome.
-a