Wirelessly posted (8700g: BlackBerry8700/4.2.1 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/100)
I see no one has responded yet. Have you figured it out?
FWIW, I get the window on 8700g. I looked in profiles and calendar options and I didn't see anything to turn the alert window off and on. Maybe theme related?