I believe with Firefox you actually have to install Greasemonkey first. From the looks of that screenshot, the scripts aren't running at all.
Unfortunately, I can't help. I'm using a Chrome derivative and it supports Greasemonkey natively - you just drag the script and drop it on the Extensions page and it installs.
Don't live for pleasure, make life your treasure...
\m/ Ronnie James Dio, 1942-2010 \m/