I'm noticing the Board now signs one out much, much more quickly than before.
Does anyone know if this is a vBulletin update, has to do with a Windows update, or is there some preference individual users can set?
A few have PM'd me about this problem. Two days ago, vBulletin found a security vulnerability and patched the software. This actually occurs more often than most realize but this patch had the effect of making any old cookies invalid.
Whenever one logs in to vBulletin and saves their login, a cookie is created on their browser that saves their authentication information. Some browsers may not be properly refreshing that cookie leading to people being repeatedly logged out.
The solution is to clear your cache and cookies and it should solve the issue.