Problem with 'checking discs'

when i try to burn a dvd nero stops responding on the ‘checking discs’ part for some time and then resumes burning. but the dvds burn are unreadable even though the disc info shows tracks written on the dvd. if i restart my pc i am able to burn a few dvds without gettin stuck on checking discs (these dvds are burnt fine and are readable) but then the problem starts again. i can burn only a few dvds at a time like this and have to restart after that. what could be causing this problem? please help

i forgot to mention that i have tried to reinstall nero and installed different versions but everytime i get same problem…