Sorry to cross post, but I couldn't figure out how to move my post from the "Adobe Reader" forum to the "Adobe Reader for Unix" forum.

If I launch Firefox (version 11) from the command line (Linux shell), then I can open a PDF with the Adobe Reader plugin.  But if I launch Firefox from the desktop or panel in Gnome, I get the message "Could not launch Adobe Reader 9.1.0. Please make sure it exists in PATH variable in the environment.  If the problem persists, please reinstall the application."

acroread is in the PATH variable - I checked ("which acroread" and "echo $PATH")

We are using acroread 9.3.2.  We tried updating to the latest acroread 9.4.something ...? but the SendMail option was missing from Edit->Preferences, so we reverted to 9.3.2.

We are using Debian Linux 5.0.8.

It is very convenient and user-friendly in our library for visitors to be able to view a PDF in the browser (with the plugin) and to be able to just click on the envelope icon from there to send a PDF.

This was working fine until we upgraded to Adobe Reader 9.4.  We reverted to 9.3.2, and everything was working fine again.  Then our systems people did some things, including updating Mozilla Firefox from version 3.6.13 to version 11.  Then the plugin stopped working from the Gnome launch panel.  I tried running the old Firefox 3.6.13 from the Gnome launch panel, but the plugin no longer works in it, either.

Has anyone had this problem?

Sometimes running Firefox from the command line gives some errors.  I tried various versions of nppdf.so and tried toggling the about:config variable "dom.ipc.plugins.enabled.nppdf.so" but nothing changed.