My Raptor died recently. Do you have SMART enabled? Oddly enough for the first time ever SMART actually did something and warned me of impending doom. So I just shut the PC down and ordered another drive and imaged the raptor accross using Acronis.
Sure enough when I got to about 65% Acronis had read problems. Thankfully I only had to end up skipping three clusters and the only casualty was Firefox. Just needed to reinstall it.