Mac – Find specs on a Macbook

You could try another memory type. I've always bought crucial memory for upgrading our Macbook Pro's and Minis and we've never had any problems.

You can't really test the memory before hand, you just have to get it and try it out.

The other thing to double check is that you have the right memory speed. See if you can figure out what speed your computer currently has and buy the same.

Those disk I/O errors usually mean you have a bad block that the drive has not had a chance to lock out yet. Modern drives automatically lock out bad blocks, but usually only when that block is written.

If you already have a good backup of your data from that partition, then boot from another Mac OS X disk (such as your Mac OS X Install DVD) and use Disk Utility to do an erase WITH "Zero Out Data" of that partition, and then restore from your backup. Note that you have to do the "Zero Out Data" to guarantee that every sector on that partition gets written to.

If I were you, I wouldn't trust that my Mac OS X partition was the only place on the disk to have a back block. I'd want to do an Zero Out Data erase of my entire drive. But of course you'd need to make sure you have good backups of your other partitions as well.