Songs play in WMP, silent/blank on H10

[KnightOwl]

I'm having a seemingly intermittent problem with my 5Gb H10 Pure, where songs which play fine in Windows Media Player are silent when transferred to the H10.

The H10 does know the name/artist/album etc, and interestingly the length of the track - when I try to play affected songs, it counts down til complete, there's just no sound. I've tried increasing volume to no avail.

Some are songs I ripped from CD as .wma, some are downloaded .mp3. No obvious patterns regarding age, format, size or bit-rate. One song may be affected among several ripped from the same CD with the others all fine.

I've tried moving files elsewhere on PC, removing them from WMP library, re-synchronsing H10, then putting files back into library and synching again (ie to force it to delete then re-copy) - same problem. However, if I remove the file from the library then re-rip the track from the original CD, it's usually fine. I have more problems with downloads - sometimes have to dowload a file 3 or 4 times before it works, although several times it's from the same original source.

This is very irritating, as of several hundred songs on the H10, it's very difficult to find all the "broken" ones and extremely time consuming, not to mention screamingly frustrating, to fix them all.

One possible clue is that I've noticed several tracks which are .mp3 on my PC but seem to be loaded as .wma on the H10 - this may be a result of the conversion used in synchronising (set to one notch down from Best Quality - 160 Kbps) or it may be the reason the H10 can't play the files - although I can't see any reason the format would be logged differently.

If anyone has seen a similar problem (and preferably fixed it ), I'd appreciate any clues you can give me as I've pretty much tried everything I can think of.

Fiona.