I'd say more ram would probably be QUITE helpful. Pipe Man's RIGHT on the mark there. 128 megs is too little with XP. But perhaps even more important is not having other apps (especialy virus scanners and adware) running in the background, not surfing the web while writing, and having a clean, defraged hard-disk. There are LOTS of tutorials available on the web to help you get that disk, your registry, and spyware/adware cleaned up so you run alot better.
Your machine, EVEN WITH 128 megs is PLENTY to burn good disks so long as it's not loaded with spyware, adware and/or a fragmented disk, but you REALLY can't be running ANYTHING else while burning man. If cleaning it up doesn't help, and you've tried different brands of good to HIGH quality media, then and ONLY then would I really suspect the drive. Let us know how you make out, and WELCOME TO CD FREAKS!