Media unavailable?

[nex1]

I recently replaced the PC that Retrospect 7 was running on. After installing Retrospect on the new machine, I can't get it to recognize the DVDs I'm trying to back up to. Backups all fail. When I try to validate my script and click Check Media, I get

 

Media for script Nightly Backup unavailable.

Writing to any disc that is erased or named "1-DVD Backup Set"

 

I've tried this with a brand new disk, and then I tried formatting it with the name given:

1-DVD Backup Set

but I get the same result each time.

 

Retrospect Professional 7.0.265

Retrospect Update 7.0.3.101

 

Thanks for any help.