Strange problem

Hello
I burned many DC gamez without problems. But now I can't more burn any games because the file image results every time as unknown with Isobuster. But it's strange because I #####ed every game before with SFV32 (and the #####sum is correct) and after I converted the file image in ISO image or in Nero image. But any file image (ISO or Nero) results as unknown with Isobuster! I tried also to burn directly with Diskjuggler (my cd-writer is compatible) but the cd results as a music-cd and don't play on DC.
Any suggestion?

Thanks

Stoccolma