Something weird happened today. Thunderbird downloaded an update and kept restarting ad infinitum due to the error “Software update failed!”. I Googled around and it turns out the Logitech Quickcam software was causing issues. Exiting that application allowed Thunderbird to update and start. How weird is that?

November 19th, 2007 at 12:33 am - Edit
I woke up to this very same issue this morning. A google search brought me here and your tip did the trick! Thanks for the tip!
May 3rd, 2008 at 11:11 am - Edit
Wow. Same thing for me. I was going nuts until I found your post. Closed the Logitech Quickcam software and update proceeded perfectly. Thanks so much for the helpful info!
May 3rd, 2008 at 5:02 pm - Edit
Glad I could help you all out