had this before... unfortunately they couldnt be recovered... the card seemed to have a dead area... it was a cheapy my parents bought for xmas. Same message. Hope you can get them back, but an inkling might be to check their file size, my corrupted ones where a lot smaller than the others.
now i only use sandisk's bought from reputable places like amazon (and i make sure it's amazon and not a reseller)... there's a lot of good fakes out there and i won't chance anything else again (after having a problem with fakes off ebay as well)
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep