Tom,
I have just upgraded to 4.2, but the void and refund are not working. The transaction i'm testing it on was placed using the upgraded module, so all db field names should be ok. When I click on refund I get the value dialog, however after entering an amount the page goes completely blank. When trying void I get the error (stored to protx_direct table) of "The original transaction not found,"
The vendorTXcode looks correct.
I have double checked the versions of the main module files and they are all correct.