Mike, I once accidentally deleated all the photos on my camera CD card. I downloaded and used the Uneraser program and got them all back

There are a few on the net for download but if you want to give me a yell, I'll email it to you, bit of rooting around but you or a mate will sort it

To test I just deleated all my GPS files on my GT11 SD card and used Uneraser to get what I wanted back

Takes some head scraching

UNERASER - DATA Recovery is a powerful data recovery software for DOS and Windows
(Console) that can recover deleted files and folders on FAT12, FAT16, FAT32 and NTFS
systems. It can even restore files from deleted and reformatted partitions. With this data recovery software NTFS drives can be recognized and deleted items can be recovered while working from DOS and Windows (Console) environment. It is not necessary to install the utility on your system's hard drive, as it fits on a boot floppy disk, removing the possibility of overwriting data which you want to recover.