Motorola SLVR L7c

When I insert a Sandisk 1gb microSD card into my Moto SLVR L7c (through cricKet) and power it back on, the screen is different and the phone is frozen - as in, none of the buttons will do anything. Thus, I cannot format the card - or do anything with the phone when the memory card is in it.

When the microSD card is taken out, all returns to normal.

Attempted a Master Reset as suggested by Motorola, which did nothing to help the problem as far as I can tell.

Any suggestions would be MUCH appreciated.

Thanks!