I had a problem with the caller ID also, although not the exact problem. I would have the S2U2 caller ID turned on and when I would get a call with it locked, nothing would work to answer the call (buttons or screen).
I ended up disabling the S2U2 caller ID. Now, when locked, it simply goes to the phones call screen. When the call is over, it goes back to being locked.
FYI. I have AT&T Tilt2 with stock WM 6.5 and TF3D 2.1, if it matters.