How to scan a DVD+RW for bad sectors?

[fmillion]

I have several DVD+RW discs that have been used for quite some time. I use these in my DVD-VR unit to record TV shows, then I later "rip" the DVD and convert the MPEG2 into DivX video.

Here's my problem...Some of the discs I'm using seem to be developing intermittent bad sectors. TMPGEnc is extremely picky (one bad sector aborts the entire rip) so I've been having to rip using other apps like SmartRipper. What usually ends up happening is that I can only acces all good video up to the bad point but nothing thereafter.

My question is I'd like to know if there's any good method for performing a sort of "surface scan" on a DVD+RW disc to see if it has some spots that actually are going bad that may never reliably hold data. Examining one disc that is exhibiting problems, the disc has no visible scratches on it so I doubt it is a scratch issue. The disc has worked fine until recently. Sometimes a "full erase" where the entire disc is overwritten seems to help, but not always. I'd just like to have some way to do an honest-to-goodness surface scan of the disc and see if it really is worth trying to keep using it or whether I should just chuck it and get more.

Some might say just toss it as soon as an error occurs at all, but it seems silly to just assume a disc is useless because of one read error.

Ideas?

[DaveS]

dvdinfo / dvdinfopro can scan a disk for errors..can't remember whether it scans the entire surface or just where it thinks there's data now (e.g. in teh case of a RW rewrite)...that said, it's checking to see if your drive can read the data; how any one application reacts to data problems may vary; and intermittant problems will show up intermittantly, even in the surface scan..but, a scratch causing a definite read error should show up... it's in the tools section