Really weird prob with DVD data record

I’ve run into a very odd problem.

I have a sony DRU501A. All I’ve ever used it before until now is recording video. Today I tried to create a data DVD . No matter what program I use it won’t record straight data.

CopyToDVD wrote it - but when I checked the disk the data is unusable. I tried with Gear - and hit ‘test’ - it gave me an error message saying that I was attempting to record to DVD but the drive I’d chosen was a CD ( which of course it isn’t!!!).
I tried my Roxio5 - which has a create Data DVD option (although I’ve never used Roxio for burning to DVD before) - it told me the same thing - that I don’t have a DVD.

Does anyone know what the problem might be?

Living in hope of a reply