3.8 Advanced Edit intermittently logging users out.
 

I upgraded this morning, and outside of a couple of manual template edits for the security token, everything else went well.

One problem, however, is that while quick edit works fine, clicking Go Advanced is intermittently logging people (myself included) out of my forum. I can't seem to consistently duplicate it, however - I can edit the same post 12 times in a row with no problem, and then attempt #13 will log me out.

Any insight on troubleshooting it would be appreciated.

Edit: This is for 3.8.6.