There might be a problem with Thunderbird extension manager cache. The operations described hereafter for Thunderbird are also available for Sunbird, even if the profile directory is different (C:\Documents and Settings\<user name>\Application Data\Mozilla\Sunbird\Profiles\<profile id>)
Before any operation, do backup your Thunderbird profile:
XP: C:\Documents and Settings\<users name>\Application Data\Thunderbird\Profiles\<profile id>\
Vista: C:\Users\<user name>\AppData\Roaming\Thunderbird\Profiles\<profile id>
("Application Data is a hidden folder, check that you can see hidden files (in File Explorer options))
Close Thunderbird
In the profile of Thunderbird:
XP: C:\Documents and Settings\<users name>\Application Data\Thunderbird\Profiles\<profile id>
Vista: Vista: C:\Users\<user name>\AppData\Roaming\Thunderbird\Profiles\<profile id>
After having backuped the following files, delete them:
- extensions.cache
- extensions.ini
- extensions.rdf
- compreg.dat
- xpti.dat
Relaunch Thunderbird
Then check the version of the BirdieSync add-on.