Computer help: DVD drives ok with videos, can't read data. software issue

DVD drives ok with videos, can't read data. software issue

Got a problem with my XP media PC 2005. The DVD-RW drives can't read DVD or CD data discs. Both drives, one is a DL burner the other is an LG DVD-RW/RAM (no dual layer), are doing the same thing. Both drives can still burn DVD Video or DVD data discs. And both drives can still read DVD video and CD audio discs. But when I insert a DVD or CD disc which is data only (folders and files), they don't show anything.

The non DL drive even says it's a non readable format. A message box comes up when I click on the drive with windows explorer. The weird part? It still keeps doing this even if I remove the disc. And after I've rebooted and I haven't inserted the disc yet, it still comes up with the same message.

I've tracked it down to software. But I don't know which software.

The reason I'm pretty sure it's software:

1 - The data discs are fine. When inserted into other computers they work just fine.
2 - I swapped out each drive one by one and put them into my other XP machine (XP pro) and each drive now properly shows the folders and files.
3 - Even with the physical media removed the software still thinks there's a problem.
4 - I re-installed the drivers for each drive, by first removing the drivers and the problem still persists.

I heard somewhere that Divx 6.4 causes problems like this. I downloaded their rollback program, ran it and nothing happens. I uninstalled Divx 6.4 and nothing happens, I installed Divx 6.3 instead and nothing happens.

I also thought it was AnyDVd but I uninstalled, re-installed a previous version and nothing happened.

Then I thought I had a virus. AVG, eWido and Avast are reporting a clean system. A few "spyware" cookies but no major virus.

Then I thought it was a rootkit but rootkit revealer showed nothing special. For some reason it thought uTorrent .!ut files were issues but they're not hidden from the OS at all.

I tried a system restore back to the earliest one I have and no luck. Booting up in safe mode still had the issue as well.

I'd really like to avoid re-installing the entire OS, thank god the recorded media I used in Media PC is on another drive, but it looks like I may have to do so if I can't find out what's causing this.

Keep in mind I have several DVD rippers (for personal usage, I'm no pirate), burning software, Anti virus programs (no crap McAfee though) and several Media-PC extensions (transcoder, e-mail, RSS reader, TV Tonic etc.)

Has anybody heard of a paticular software which when installed will suddenly start doing this crap?