Forum Idle time

I hope this is not a n00bish question, but is there anyway from my UserCP that I can prevent being automatically logged out for idling too long on the forums? I was about to post a rather lengthy OP for a new thread, but due to long "inactivity" when typing, was automatically logged out when I tried to post the OP/thread, and lost the entire content! This has happened 5 times already with that thread I was trying to make.

Just a simple vBulletin feature request/problem...

This never happens to me. I'm still on this log in, and it's been a couple years.