Help! The ring and notifications I never get!

[blueandwhiteg3]

I have an HTC Titan. Updated the ROM after getting it, all seems fine. Minimal extras - just SPB Pocket Plus and a few other pretty standard goodies.

The problem I have is that I am missing calls. Or more precisely, I am missing the notifications.

When I return to the phone and it has powered off automatically OR I have turned it off with a simple tap of the power button, when I touch the power button, I immediately get a fraction of ring, see the call coming in, but cannot answer the call. Then I immediately get any sms or voicemail notifications. This happens even if the call was hours ago.

More interesting, the calls also appear in the call log to have been missed at the time I powered on the device, not the time they actually arrived.

What am I missing here? This seems like a pretty big functional problem with some hopefully simple solution! Any suggestions short of an agonizing hard reset?