If the simm's were lose (which they were since the cheap, plastic locking tabs had broke off), they could have shorted or more than likely shorted out the part of the card that detects/uses the add on ram. About the only practical thing to do is desolder the old simm slots and solder in a new pair, then test with known working simm's. Good luck and let us know what happens.

They sit pretty well inside, they dont move in any direction, thats why its strange.