Something is wrong(read positions)

I was writting perfect with 2 asus 5232A3 cd-rw with no problems with nero burning rom 6.60 until i dont know what happened and when i write with both recorders
it seems that one of them is writting faster and i get read positions in the begining 1-2% and at the end 80-90%.
and i dont know which one exactly because one time is the one that writes faster and other time is the other.
I bought 2 new recorder lg and the same thing is happening.i changed to nero 7 ,the same.
I was doing some overclocking before that happened ,now i am back to normal,but the problem is still here.I am thinking something does not work properly ,maybe its the cpu??the memory??temps?hard disk?
i have pentium4 530 3 with 1gb ram how i can figure it out? .
i ve changed cables ,i have put them together in first ide cable ,the problem is worst but i can understand that cause they are on the same cable.
Will this read position make any difference when i write music (will it jump or smthing?) ,i dont get any buffer underuns error.
please help im going crazy here :sad: