Problem with Cisco Wireless Card and Possible Overheating

I have a Dell Inspiron 1100 laptop (about 3 yrs old) that has been giving me two problems:

1) Yesterday is spontaneously turned off. The battery was charged, and it didn't shut down first--it just suddenly turned off. I tried to boot it up and it just turned off again. It seemed to be working ok later, but then it did it again, after the computer had been on for just 20 minutes or so. Could it be overheating? Is the battery fried? It seems to be working ok today. I'm not sure what to check it for.

Then yesterday *after* this problem started I had it in a backpack on a chair and the open bag fell on the ground. The external wireless card was in and that is about where it hit the floor.

2) So then this morning (the next time I tried to use it) it wouldn't recognize my external wireless card (Cisco Systems Aironet 350 series). The computer seems ok, but the card isn't registering at all. It's as if I don't have a card at all, but it's definitely inserted fully and properly. Did I break it? It doesn't look any different.

I can't think of any way that the two could be related, but I thought that I would check. Any advice would be immensely helpful, either on the card or the spontaneous turning off.

Thanks!