Keyguard on Treo650

I was wondering if anyone else has experienced this problem.

I have a Treo 650 (Sprint) that I normally carry around in my pocket. To prevent the buttons from getting pressed, I use the Keyguard feature. With Keyguard, turning on the Treo650 requires pressing two buttons instead of the one that is required without Keyguard. This works really well and my Treo650 almost never gets activated by accident when it's in my pocket.

Now I'm really enjoying the Bluetooth feature on my Silver '06 package 6. But sometimes when I power up the car, I start hearing clicking sounds from my pocket! The clicking doesn't stop unless I take the Treo out and shut it off. It seems that when the phone connects to the car through Bluetooth, the Treo turns on and the Keyguard feature gets unlocked (as if I'd pressed the 2 button sequence myself). And since the phone is just sitting in my pocket, the buttons get pressed, producing the clicking sounds (along with other surprises, like a new memo that consists of hundreds of the letter "S").

This is really annoying. I think it is a Treo problem, not a Prius problem.

Has anyone else experienced this issue? Anyone have any suggestions for a solution? I suppose I could buy a case with a cover, but that would be equally convenient for other reasons.