Moving to one 1gig from 512 won't directly improve your burn quality if you are not using the computer until the burn completes. If you are surfing, writing "Letters to Mable", or whatever while encoding/burning, the increased resources may very well play a part in reducing the chance of errors.
With that said I would consider adding a HD. I'm not one to walk away and not use the machine while I'm burning or scanning. I've installed a seperate drive (200gig sata) just for burning apps and ripping storage to insure no additional drive activity on that drive at the time. This allows me to do anything on the machine without effecting the burn and has certainly improve the reliablity of my burns.
Just FYI: I use a SATA drive (WD Raptor) as the OS/Boot drive, another Raptor for Apps, Data, Utils, and Misc. And the WD 200 SATA for DVD stuff...... This also frees my IDE channels for optical. This config works great for me. :iagree: