I just found something very strange (to me, anyway). I ran Firefox from the Mozilla installer. Then I clicked on a link in Thunderbird, which caused the Debian version to run. But instead of launching a separate window, the link opened in the existing window. But after doing that, when I went to Help>About, the version information changed from 1.0.6 to 1.0.4-2 provided by Debian! Same window, same open tabs, but suddenly it says it's the Debian version instead of the Mozilla one.
How is that possible?
