Realport, MSDOS and XP

I am setting up new XP boxes with the Realport driver which an ancient MSDOS app needs to connect to COM2.

Older XP boxes (which are being replaced with the above) with an early 2006 version of the driver seem to work. With the new driver, the app. seems to be able to connect to COM2 but no data seems to flow. Are there any registry tweaks or settings I need to make a DOS app. work on COMx?

The fellow who has been through all these issues is on the other side of the planet for 6 more weeks so I need some help from the forum.

I doubt this is a supported use, but, if the DOS app only talks to com2 and does not try to use the IO port address and IRQ, it may work.
Though possible, I doubt that the issue is that the old RealPort driver works but the newer RealPort driver does not.
I suggest that you do this 1 step at a time.
Start by testing the port with Hyperterminal and the loopback plug installed in the port associated with com2 (presumably port1). Here is a link to instructions, if you need them:
Be sure to use the same port parameters which your DOS app needs (example: 9600, 8N1).
If the Hyperterminal test works, then the DOS application has a chance of working.

Reconnect the serial device. What are you connecting to the port?
Try your application again.
What are the results?
What port parameters does your app use?
Which Digi product are you using?
Are you using the exact same product which was working with the older Win XP PCs?
Which port on the Digi are you using?
How is the port configured?