I have a UA25 and UA101 both are USB, I use the 101 now as it has more inputs.
One quick check do you have the UA25 button on the back selected to advanced?
I'm sure it will help with the driver installation, I can't remember off the top of my head but you will have to have it set to advanced for it to work with sonar. Your original problem was cured by changing the drivers from WDM to ASIO or vice versa.
The Roland driver definately works though.
Have you a restore point you can go back to post driver installation so you can start agin?