I'm not sure mate, I see you have a version 4.
I would try recal your laser as other members have suggested. If you can't do it yourself then get the person who modded your machine to do.

I've had a GT version 4 back because of gtavice city errors. Would work fine on my panasonic dvdr but not on the media he used(can't remember what is was sorry) Recal the laser and it worked fine.

Hope this helps