pastel accounting error = 46; file = 41; opcode = 3

Hi there,
I have Pastel version 4. This doesn’t want to go with Windows XP. Have therefore re-installed Windows 98 on old Pentium 3. Everything runs but when I tried to copy my back-ups, you can read the files but when you try to book or print, the above mentioned error codes pop up… Pastel does not give support and I’m sure this must be a relative easy problem. I however do not know where to start.
Thanks.