Okay guys, I'm on my way, but something seems to be wrong...

I replaced the RAM, everything was fine. I updated to Snow Leopard (thanks for your help, Tom), and the entire process went great. Overall the laptop still runs just fine and seems to be working great.

...except for one problem - WiFi. For some reason, now the WiFi seems to be dying randomly. I'll just try running a system update and it'll say there's a network problem. Then I'll try going to a web page and it can't connect. The only thing I'm able to do is to turn the Airport off, wait, then turn it on again, and all of a sudden everything is working again and works just fine. I was able to download over 1.1GB of updates over WiFi, but then the laptop sat for a little while and I came back and it wasn't working again.

None of the other devices on my network have problems connecting. This laptop its self had no problems connecting before these upgrades. What's going on here? In the only instance I could find online of this happening to someone else, the entire thread was spent blaming various routers (never the hardware or software). I'm not saying I love my router (I hate it), but I can't fault it when it's humming along just fine as far as everything else on my network is concerned...