How can I set different taskbar icons for Firefox profiles in Windows 7?

If somebody is OK with running beta version of FF (or Aurora or Nightly) then installing and using stable with one profile and beta with the other one seems to solve the problem.

• it's possible to pin both profiles to taskbar
• these profiles can have different icons

How to do it:

1. Install stable version of FF and beta version in separate folders (you can get beta from here)
2. Create second profile using ProfileManager
3. Add to the beta shortut target parameter -no-remote -p yourprofilename
4. Change the icon simply by rightclicking on the pinned icon, rightclicking properties and the icon menu item

It seems to works flawlessly. If somebody has a way to run two stable versions in this manner I'll gladly accept such an answer.