I have been using iFolder 2.1 client on my G5 iMac succesfully for over a year. However, I just installed the updated mono framework (v and client version 3.7, and now iFolder does not launch.

In the Finder, the iFolder 3 icon is superimposed by a translucent crossed out circle. When I launch it, I get an error that reads:
You cannot open the application "iFolder 3.app" because it is not supported on this system.
I downloaded and installed the correct versions of both the mono framework (first I tried PowerPC and then Universal) and iFolder (for 10.4.11), but no combination worked. I looked for an old version of the iFolder client without success, and when I tried to install an old version of mono, the installation failed.

What's the cause of this problem, and what can be done to fix it?