You should try ripping the wav twice, while noting the checksum after the first run...if the checksum of the second rip is the same, you can be pretty sure you have a perfect rip. In that case, if sound-quality isn't good, it's still the best you can get from that CD...
I always do a 'grab', and then a 'test': that way i get two checksums to compare and only one wav-file.
Could use EAC instead, but I don't like it...