i dunno if this has been posted already
i have an 8100 and just at random times it will say SIM ERROR has any one else had this problem with there blackberry

Wirelessly posted (8700g: BlackBerry8800/4.2.1 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

Happened to me. Pull and gently clean the contacts on the SIM, and replace to BlackBerry.
You may need to exchange for a new one with your carrier, if it continues.
Good luck.

you have to make sure its strapped in properly too, sometimes it comes loose