I run XFCE4 on my laptop and have been having all kinds of issues with getting Mozilla Firefox to work properly. The main problem I have is clicking on links in other applications. In gaim, if I click a link, the link opens in my currently open Firefox, but also tries to start a new instance of Firefox, bringing up the annoying "Select Profile" dialog box.

Clicking a link in Thunderbird, of all applications, does nothing. I have to copy/paste the URL to browse links from there.

I have the environment variable "BROWSER" set to "firefox", which is, I understood, how to set the browser in XFCE.

Advice Appreciated.

Hmmm.... are you using a touchpad on your laptop? Doesn't really sound XFCE specific, maybe the sensitivity settings on your touchpad? I'm just throwing out wild guesses here - I run FireFox/Thunderbird under XFCE without any problems on an old PI laptop and on my desktop.

It does see the click, as it outlines the link in the dotted box. This problem occurs both with touchpads and mice on the box.