RAM Question

No. I have the same machine, and I've been using it for nearly 3 years with a 1GB stick of Apple memory and a 2GB stick of Crucial memory with no troubles (other than 3GB being somewhat less than what I need for the applications I use, that is).

 

It is said that for 'best' performance you should get matching pairs (not just brand but lot etc) but in reality as you just heard lots of people do just fine with mix and match.

 

Your MBP will do asymmetric dual channel memory, which means you lose very little performance with unmatched memory modules, a few percent at most, and it will not be noticeable in real-world applications.

In the days before just about all chipsets did asymmetric dual channel, having unmatched modules would put the memory in single channel mode, cutting the theoretical speed in half. A bunch of the RAM in my desktop computer just died, and on the single remaining good stick it is really slow, even though it isn't running out of RAM, and XP should be fine with 1gb.