It may be that you have a resource hog running while you're trying to burn a disk. Is it possible your burning software has been "upgraded" recently? Have you recently run a big Windows "Update" (NOTRIOUS for wreaking havoc on an otherwise stable system)? What about your antivirus? Is that new or updated? Antivirus can be a resource hog, too.
Outside of that, have you looked to see if others have had similar problems with that optical drive? Perhaps there is a firmware upgrade that addresses your issue.
Optiarc isn't a bad brand name, although I think that both NEC and Sony made more stable drives seperately (especially NEC) before they got together as Optiarc. I'm not inclined to think it's wearing out, but that is certainly always a possiblity.
"I have a PhD in horribleness!" -Dr. Horrible "Dr. Horrible's Sing-Along Blog"