Vynucení instalace staré verze doplňku

rename .xpi to .zip
open the file with winzip
edit file install.rdf
change line 50 from
<em:maxVersion​>3.0.0.*</em:maxV​ersion>
to
<em:maxVersion​>3.0.*</em:maxVer​sion>
update and close the .zip file with the new install.rdf file
rename .zip to .xpi 

Synchronizace kontaktů Google

• Zindus - ale nefunguje s TBV24.1
• CalDAV
  http://www.ghacks.net/2012/12/15/sync-google-contacts-with-thunderbird-using-carddav/