I noticed this problem before, but since the other buttons on my Logitech keyboard (incl play/pause, volume, fwd, back, stop, mute, back, search, scroll, email, and Home) all work fine, even when MJ does not have "focus", I haven't worried about it. And note, I have
no Logitech software on my PC.
I believe this Media key problem is due to the fact that XP does not recognize MJ as a Media Player. This is different from the File Type associations (for things like .mp3 and .jpg) Look at the
Set Program Access and Defaults screen in
Add or Remove Programs in the Control Panel in XP SP1. When I click on Custom, MJ is not listed as a Media Player. Only WMP is listed, and pressing the Media key launches WMP.
My guess is that if MJ can get listed on install (and MJ is selected as the default media player), the Media key will work. Downloading new Logitech software and editing their .ini files probably works for some people, but getting XP to see MJ as a Media Player is a more elegant solution.
Also, on the Logitech website, they list about 18 media applications that its keyboard software supports, but not MJ. I suggest that J River contact them to be included in all future software.
http://www.logitech.com/index.cfm?page=downloads/software&CRID=310&contentid=5055&countryid=19&languageid=1