Got it,
This may not come as much of a surprise, but this is, again, a problem with vBulletin 4.
The problem, after a ton of time spent looking through the code, is actually in the latest update.
It's listed as the biggest issue (among many) for vBulletin 4.1.10.
https://www.vbulletin.com/forum/show...Release-4-1-10
We have implemented the fix. Please download and re upload.