Nero + pioneer dvr108 trouble

I have a pioneeer dvd recorder and use nero software (nero 7 i think). I was able to burn dvds fine until a few months ago when i formatted my pc. Ever since the format i’ve been having trouble. When I try to burn a dvd, it starts fine, but after nero starts burning it tells me the time remaining is 5 minutes, and it counts down from there. When the time reaches zero, the burning process will be aborted, which generally cooresponds to 40-55% complete. (ive noticed that i can copy and burn cd’s fine, since it takes less then 5 minutes). Anyone have any idea what the problem is?