i've noticed this after installing os4 (previously jailbroken/unlocked). and i religiously close apps that may be running in the background so that's not the cause....
This sucks... I had excellent battery life with 3.1.3. It would last days, even with 3G and wifi on. Now I can watch the percentage drop as I'm looking at it.
I've heard reports of this from others as well, it seems to be linked to the jailbreaking but I'm not 100% certain of that.
You can try UNjailbreaking and doing a restore to compare the drain rate, just to rule that out as the cause. You can always re-jailbreak if that doesn't turn out to be the culprit.
Yeah, I'll do that.. I will lose my unlock though, but since I saved the blobs from 3.1.3 I'm pretty sure I can downgrade if I have to. It's an AT&T iPhone, so I need the unlock.