I have the same problem, so i tried a few things. I work at Circuit City, so i'm there pretty often....so i bought some different alarm clocks and tried them out. you know, to see if somethings would wake me up more "easily". After trying about 8 clocks(i returned one, bought one, etc...) I decided to try one of those new-fangled Zen Alarm clocks. So i went to eGay, and found one for $80 shipped($100 MSRP). It's ok, i guess. It's a nice looking piece in the bedroom if nothing else. It doesn't wake me up any better, but maybe that's because i'm not using it to it's full extent. I guess you're supposed to say your "daily affirmation" stuart smalley style when you hear the first Ding.
Anyway, i can't help you on your problem, except that letting you know that a different alarm clock does. not. help.