I think I found the solution, courtesy of a smart person on the Internet. There was a discussion on the apple forums where I found the answer. Here's the apple site:
https://discussions.apple.com/thread/6723850 and the answer is here:
Windows Phone 7 and OS X Yosemite
In a nutshell, you have to slightly edit the Windows Phone app. Directions use terminal to do precisely that. Before you start, I suggest you save a copy of the original app just in case things go awry. I already did the work for using with Yosemite, and tried it with Mavericks (still works!). Will update to Yosemite and post my results...once I get the Time Machine backup done.
[edit] I can confirm that this worked with my machine. Got the Yosemite update done and the modified Windows Phone app works!