Thanks for the advice. I downloaded and installed SP2 last night. Whatever it was, things are still running smooth. With my new laptop purchase, though, I was able to get a free upgrade to Windows 7 - but I think I'll wait on getting that, too, when it comes out. Should be like Decemberish.

As for malware, I used to be a firm believer in SpyBot and AdAware. But anymore, I am loving MalwareBytes. What a great piece of software.