I think I figured out why I may have been missing calls lately. I commonly carry my T68i in my pocket, and have had it vibrate. I take it out, and am staring at a PIN: screen. Testing a few things, I tried holding down the no button while the phone was locked. I then proceeded to call my phone, and sure enough, the phone blanked out and reset, and the line gave a fast busy.

Can anyone else with a T68i try this and post their results? Also check the firmware version you have, I am thinking it may be a firmware issue. Mine is R3C001. To check yours, do the following sequence on the phone:
> * < < * < *
With the < and > being left and right on the joystick. Then go to Service Info and Software Information.

I'm trying to see if I need to replace the phone, or send the phone to the 1 service center in the US for a firmware upgrade.