On a variety of different recorded programmes. I had thought about a low level format, but the fact that I'm getting this on different programmes suggests to me that it may be whatever it is that reads the disk that is at fault rather than specific places on the disk.

Any suggestions? Would a ll format help?

Is it worth replacing the disk (on a 3yr old machine) or better to buy a new one (gulp)

Thanks

A format in a PC costs nothing and might help. Run chkdsk after formatting and if there are any bad sectors reported then the disk should be replaced.

Your call. personnally I would fit a new disk. It is easy and a fraction of the cost of buying a new box.