Desktop Launcher mystery

[Dave Stevenson]

For quite some time I have used various desktop launchers for quick
access to web pages on my home network.  These survived upgrades
through several versions of Ubuntu up to 9.10 64-bit.  After running
into a couple of 64-bit related problems, I did a fresh install of
32-bit 9.10, retaining ~/ on a separate partition.  Since then one of
the launchers opens gedit instead of Firefox.  I've been searching for a
solution for days.
Here are the contents of three .desktop files.  Two of them work OK, the
other opens the page in gedit.

[Desktop Entry]
Encoding=UTF-8
Icon=text-html
Type=Link
Name=FeedTime.desktop
URL=http://pch-a100:8883/feedtime.cgi
Name[en_US]=FeedTime

[Desktop Entry]
Encoding=UTF-8
Icon=text-html
Type=Link
Name=NZBGet.desktop
URL=http://pch-a100:9999/NZBget_web/
Name[en_US]=NZBGet

[Desktop Entry]
Encoding=UTF-8
Icon=text-html
Type=Link
Name=Webmin.desktop
URL=https://localhost:10000/session_login.cgi
Name[en_US]=Webmin

Any suggestions would be very welcome.

Dave