Another followup.  Tried it at home on Ubuntu 9.04 32bit and Firefox 3.5.3 and the problem is still there.

Just to follow up.  I disabled all of my add-ons/plugins etc except for firegpg and restarted.  The problem was still there.

Same here.  Successfully decrypts, but cleartext is not displayed.  Using: Ubuntu 8.04 64bit, Firefox 3.0.14 with adblock, autopager, xmarks, gmailmanager, download statusbar. 

I am able to mouse select, decrypt, and view blocks with firegpg manually.

Really nice app.  Thanks for your work.