TBS will not open saved file

I have an issue that developed twice now with tbs. I was working on a project …saved the project and then later when I try to re-open the file I get a error message stating that …“xxxx.tbp is not a valid tbs file”.

This last case is will be very painfull if I cannot somehow recover this data because I have invested substantial amount of time in it.

I am runnimg this on a 1 month old Tablet PC I bought from Gateway using TBS 3.0 …the updated version.

I was working on the file for several weeks now and made my last save just 5 hours before receving this message …so its not like I had a very old file on my system.

Can someone help?