Ritek does, and always has, sell OEM media with varying specs and materials. So one batch of G04 does not always equal another. Add to that the fact that quality control between batches is variable, and what you get is media that is at best variable and at worst unreliable. G03, G04 and G05 have all suffered the same issues, as has the R01 and R02, etc.
We have seen the same complaints here ever since people have been testing media, that one batch performs very differently than the next. Some burners seem to aggrivate the differences. Of the larger Taiwanese media sellers, Ritek generates the most complaints here as far as DVDR goes.
Personally, I would not buy Ritek, there's other options that are more reliable. There are burners that generally seem to handle it very well, like Pioneer and NEC, but many burners just puke it out.