Comment 6 for bug 54663

Inside a terminal can you try running mozilla-thunderbird -profilemanager and creating a new profile to check whether or not it's an issue with your profile?

To get a debug package you'll need to add a deb-src line to your sources.list.

Add this line to /etc/apt/sources.list:
deb-src http://security.ubuntu.com/ubuntu dapper-security main restricted

then run apt-get update, beforegetting the source package.