Signature makes send fail

It quite often happens to me that Thunderbird hangs when sending an E-mail. It simply stops exchanging packets with the SMTP server (have traced this with Wireshark). The problem is NOT with the mail provider, I have this problem with 3 or 4 different providers. I can cancel sending, but when I try again, it hangs again. With different mails, it hangs at different stages (percentage), but the same mail reproducably hangs at the same percentage. I have eventually found out that this is caused my my signature: - When I create and send a new mail, it works. - When I reply to a response of the first mail, it fails - in order to send, I need to delete the innermost signature (belonging to the initial mail, and through the reply part of the second mail). See screenshot - I need to delete the marked signature to send it. I use this signature: -- --------------------------------------- Torsten Thiessenhusen Dental IT Service www.xxxxxx.dk kontakt@xxxxx.dk +45 - 12 34 56 78 Dental IT Service er Uni-Tel forhandler --------------------------------------- The signature has been created through the account settings. For different accounts, I have different settings, but all following the same scheme. There are no embedded images. The problem has existed across a few versions of Thunderbird See also the attached image. Could anybody explain why it fails, and tell me how to have this problem solved? Rgds, Torsten