Well ...
Thinking, then, this is the way to backup configuration data, I went to the user I used to set up the v572RF32, went to HKEY_CURRENT_USER\Software\VB and VBA Program Settings\v572rf32 and exported the entire folder.
Then, I went to the other user (that had all default data) and imported my previous export.
Running v572RF32.exe, I saw the opening screen '16 bit regular X10 devices' now had the proper boxes either checked or unchecked, as my custom setup. However, clicking on 'Show First Group' resulted in: Run-time error '5': Invalid procedure call or argument.
Returning to regedit and deleting the entire HKEY_CURRENT_USER\Software\VB and VBA Program Settings\v572rf32 folder and re-running v572RF32.exe, my settings were back to default, and clicking on 'Show First Group' now worked again.
Something must still be up, as I could not have transferred settings from another computer.
NOTE: Thread hijacking not intended.