Burned Dvd Won't Mount


Hi there,
Since I upgraded to 10.3.9, it seems I have a real hard time to get my own burned DVDs (Toast, Mac & PC data) to mount. CDs and commercial DVD will just mount fine. Those DVD that won't mount will mount just fine in a recent G4 powerbook 12".

My config : G4 "Yikes", Pioneer 106 CD-DVD burner (firmware updated to .

I did not managed to see those discs on Disk Utility.

Any hint ?
Thx for any help.

Since I upgraded to 10.3.9 some Cds burnt on PCs won't mount, mainly 52x speed - is this a related problem?
I can see them in Disk Utility but the are greyed out, as is the button for mounting.