OK try this then. Because you changed computers and Windows was 98 and now is XP, printer driver names are different between these operating systems. Win98 attaches an 'on LPT1' at the end and XP doesn't; this is enough to make things different, and if Adagio Checks cannot find the printer with the exact name, it will pick the default printer.
So you may need to 'reselect' the driver. Go into File-Options, and select a new printer driver, save the change and close the window. Then go back in and select the printer you want to print to (NT 40, correct?). Hopefully this should help.
To answer the rights issue question I asked previously, you indicated a single station but I couldn't tell if the program was installed locally or on a network. I take it everything is local then. In Windows XP, you can have different things appear depending on which user logs into the station; I would recommend doing all of the printer setup while logged into Windows as the user rather than Administrator to avoid different things being loaded by Windows.