Recently I have been having trouble using EAC with my NEC3540A. It seems that most of the time CDs (not bladly scratched) have a track or tracks (sometimes at the end) with a "sync error" (and Acurrate Rip shows this track "not accurately ripped").
Sometimes I take the disc out, Clear CRC values, put it back in the drive and either it does it again or I have to keep doing it until it doesn't. Sometimes I clean the CD before returning to the drive. Eventually no errors will occur with the CD, but takes many extractions.
I also notice that if I restart the computer the extraction speed will change dramatically.
I had these problems with EAC beta 2 and 3 now I am on beta 4 and its the same thing. I have also noticed this with my benq1640, so it doesn't look like its just the NEC.