Run Time error 440

I have recently taken over a VB application that scans a directory for ASCII text files and loads data from these files into an Oracle database.
This being my first exposure to VB, it's rather a baptism of fire.

Over night when the program is just continually scanning for files the program crashes with the following error

Run-time error '440'
OIP-04108 : Invalid row reference

Could anyone point me in the right direction to solve this??

Many thanks

What version of your oracle db?

We recently upgraded 9i to 11g and VB apps started showing this error.

Thanks,