[Treo] My Treo keeps waking up

[john.messeder]

My 680, with a custom ROM (though I'm not certain that matters) keeps 
waking up. The screen comes on and the keyboard lights up, lots more 
often than the every 15 minutes Chattermail is running a check for new mail.
    It lights up, goes blank after about 10 seconds, and lights up a 
minute later.
    Anyone know what's going on? and more importantly, how to make it stop?