I've recently made the switch to Firefox 4, but today I found that Minion has not been updated for Firefox 4, but don't fear.

It seems that latest version does work fine* under Firefox 4.

You just need to change the maxVersion from 3.6.* to 4.* in the installers install.rdf file.

Just follow these steps:

1) Download the plugin from https://addons.mozilla.org/en-us/firefox/addon/music-player-minion/

2) Rename the .xpi file to .zip

3) Open the .xpi file

4) Open install.rdf in a text editor (notepad, gedit, etc)

5) Change the value maxVersion from 3.6.* to 4.*

6) Save the changes to install.rdf - ensure the changes are saved to the zip file.

7) Rename the .zip file back to .xpi

8) Install the modified .xpi file in Firefox 4 (drag and drop into firefox works)

* Note: My playlist's alternate lines are a light grey background with a light yellow font - almost unreadable - Any ideas what's causing this?