I thought I was going to keep it at 6.5.2, but I think I'm going to roll back again, mostly to appease those who make long posts. The 6.5.2 added some new session stuff that can't be easially disabled, and it's already aparent the setting of 180 minutes isn't working properly. This is what results in the "Form no longer valid".

Since 6.5.0 and 6.5.2 can mostly coexist on the same database, I'll throw it on a test install later and try to tweak everything a bit more.