Got a straight talk sim and a card for a month unlimited everything. Put sim into unlocked droid 3 and get "invalid sim" or "gsm/umts networks found" when I put it in gsm mode. I created an APN just like it said to do on straight talk's site. I've done battery pulls, airplane mode, even wedging a piece of paper on top of the sim card to make it fit more snugly. What am I doing wrong? Also I don't know if it's relevant, but the sim card came in cheap straight talk phone I bought and I activated the sim in it first.