Is there a Script to Backup Cartridges?

[snipa]

I dumped a couple of carts last night with mixed success.
One worked OK as far as I have tried it.
The other one boots fine and plays fine as far as I have tested it but it is missing some SFX bizarrely!
Very strange....

I've tried it more than once, too with the same result each time. On both dumps, the file structure was identical in the number and size of files.