Corrupted file names

Has anyone had any problems with wierd file names when loading from compact flash?
about 80% of the times i load stuff off my cf card (lexar 128mb) it shows the first 2 or 3 file names perfectly, but the rest are a bunch of wierd characters!
Ive managed to remedy this by ejecting and reinserting the CF card until the mpc reads the names properly (normally have to do this about 3 times), but I wanted to know if anyone else has this problem, and, even though its not a big deal now, will it develop into a more serious fault?
Any help would be really appreciated.

have you tried reformatting your CF card?

Yeah, When i got my MPC (its 2nd hand) it had the card with it, but I loaded the sounds off it, and reformatted it in the mpc straight away.
I had a little trouble doing it (it took like 5 times) because the mpc kept saying "format invalid", but it eventually worked.
Do you reckon the card is damaged, as I have no idea how old it is?
Or could it be a prob in the mpc?
thanks again