Hi HandyAndy14, after the trouble I mentioned with the driver listed above, I went through the other options. I can't recall if this was listed among them, but one of the things I did to improve performance was run CHKDSK. Since then the issue appears to have disappeared! Hopefully it will last, although I couldn't see anything in the CHKDSK log about finding bad sectors or anything. If the issue returns I'll come back with more questions :smileyhappy:
Thanks for your help. It's very much appreciated!