Just a suggestion here: - copy the contents of sig elsewhere to avoid losing. - delete sig file. - exit and restart tb - create new sig file. This may not work, but then again, it may.

OR, if you're comfortable dealing with HTML, install the HTMLedit addon and view what the HTML looks like in compose window to see what is causing the overlay.

Thanks David. I'll give it a try.

Can we see the contents of the file? This forum is basically pretty poor when dealing with raw HTML. But you can email me at devilsgatedrive@gmail dot com and I can have a look at the message source. My guess is the original code was generated and some update to Thunderbird has modified the handling of CSS. Probably implementing some long codified standard that has been ignored for years. Only looking at source will offer any real clues though.