it could still be bad media...i don't think G05s have a very good reputation.
also, you didn't list your burner or firmware, but make sure you have the latest firmware.
you also didn't list what speed you were burning them at. burn at the rated speed (never the "max" setting)
what are you using to remove copy protection? shrink is rather outdated. I have no idea if this is a protection issue, but to be sure you can download a trial of anydvd from www.slysoft.com and that will rip the crap out of those movies.
you also didn't mention version numbers of any software you're using.
so update the firmware, burn at a reasonable speed, decrypt/rip with anydvd's ripper (version 184.108.40.206) and transcode/burn with clonedvd 220.127.116.11 and let us know how it goes.
also, are G05s +R media? be sure that your standalone is friendly with +R media otherwise check to see if you can booktype (bitset) the discs to -ROM while burning. some drive sallow this and some don't.
that's just my $.02!