Mac is shutting off when iPod is plugged in. Please help.

I have a MacBook Pro with Mac OS X version 10.6.8

I went to plug my iPod (gen.6) into the 1st USB port (the on closer to the headphone jack), and it shut my Mac off. I turned it back on, and everything seemed fine. So I tried plugging my iPod into the 2nd USB port (the one closer to where the charger plugs in), and it wasn't reading my iPod. It turned the iPod on, it was changering, and that was about it. So I tried the 1st USB port again, and it turned my Mac off again.

I've also tried my iPhone, and it does the same thing.

After turning my Mac back on, again everything seemed okay, I plugged my flashdrive into the 1st USB port, then the 2nd USB port, and both of them read it fine.

I've tried the SMC restart thing, but I don't know if I'm doing it right.

I've plugged both my iPod and iPhone into the wall outlet, and they don't seem to have any problems. Could it still be the cord though?

Also my iTunes Library recently had to restart itself the other day (before all this started to happen) cause it was damaged. I don't know if that has anything to do with this or not.