Here's how to set a file association in WM 6.1:
1. Open File Explorer and find a file of the type you want to associate to an app.
2. Hold down the stylus on the file name for a couple seconds (til you get the context menu) and choose "Open with program..."
3. Choose a program from the list on the top part of the resulting window, then check the box labeled "Associate selected Program with this file type."
4. Hit Open.
5. You may get a message to overwrite current association if there was a previous app associated with the file type, chances are you'll want to go ahead and overwrite so it will remember the association you prefer.
This works great if you want to open some multimedia files with one program and others with a different program. For instance, I couldn't get Media Player to open my .AVI files, but it was the default association, now I set .AVIs to TCPMP and all is working great! ( I know TCPMP is one of the few programs that lets you set the association, this is just an example - and it was actually easier doing it as described above!)