1993 Pontiac Bonneville security lite on dash lites and sta

Car runs fine and starts fine usually but when you stop and turn it off sometimes it won't start and the dash has a lit security sign which stays on. Dash lites come on but nothing else does. The ignition key has a chip on it which I have been told is for theft prevention I have had to replace this key and have had two made. Both at the same locksmiths. The car will usually start in 10-15 minutes I have tried getting out of the seat, opening door with car key running gear shift thru all gears, turning ignition key on off in out putting my seat belt on off, finally it will start, like I said it acts as though it doesnt recognize the key chip for a little while. Or as though some security feature thinks I am stealing the car. I have been told I might need to get a factory key for ignition This is driving me nuts. Please help.