Friends making coasters

[scottvf]

I built my friends computer which is the same as mine (same mb, video, burners, ect). He uses the same software as me (I taught him how to rip, shrink, and burn) But he gets errors every so often when burning a dvd. He would defrag and reboot then it burns fine. But I hardly defrag and never get coasters. I even search the web while burning and haven't had a problem.
I thought it was his burner was defective, but I put it in my computer and it worked fine. It's a sony dru-510a.
This has me baffled why he has this problem every so often and I don't.
Any suggestions?

[Bob W]

Maybe check in windows device manager to make sure DMA is enabled on the Sony.

[johns0]

No 2 computers or burners are quite the same even with the same brands or parts,other factors include media,burning programs,programs running in the background,o/s,ram specs/ide drivers crapping out...blah blah blah,the list goes on.

[Bob W]

Yeah I forgot about RAM problems so you could check that out by slowing down the memory speed in bios.