DMR-ES10 'unformat' problem

Hi, I got one of these DMR-ES10 DVD Recorders a few weeks ago because of the good advice from the fellow members of this forum. It has been excellent up until now. The problem is… when I put in a DVD RAM (I use Panasonic discs), it now says ‘unformat’ on the display. This happens more often than not. (This has happened when I put in discs that I have previously used for recording and on new discs that are just formatted and haven’t been used yet.)
Then when I go to format the disc, it says that this disc is not writable and it won’t format the disc.
It is also starting to not ‘read’ blank DVD-r discs that I go to record onto, even though it will then ‘read’ discs out of the same spindle.

I’m planning on taking it back to the shop to change it for another one as I was more than happy with it before this happened, but I was just wondering if there was a simple explanation for this?

Thanks,

millsybjj

Sounds like a bad drive.