you can't afford cheap media. Really. Assuming known good media costs twice the price of these cheak blanks, and if there is a 50% bad burns rate, then the price advantage has vanished.
You might also try Sony discs, perhaps these are slightly cheaper than the Verbatim.
i had no problems...when i bought the dvd writer before flashing it,well recently i tried burning using a gimik disk and it burn's successfully but it wont read...
So this is clearly a media issue.
any suggestion's...& is there a way to restore the firmware to its previous state.
Since you flashed back to the original Sony firmware, you should be fine.