Corrupt Data in My Invoices and Estimates

Hi!

One of my friends is using My Invoices and Estimates by
MySoftware.com. He was contronted with a message thos morning saying
his invoicing.inv file was corrupt but he doesn;t have a backup file
that is satisfactory.

Is there a repair utility out there he can use? Repair service? Are
the files in a standard format of some kind?

Any help anybody can offer would be appreciated.

Frank