When changing the image/photo for a contact in Thunderbird, the change is not detected and subsequent sync fails to update the entry.
There are two scenarios, both where the contact entry is common to MPE & Thunderbird and where there is no photo to begin with:-
i) Adding a photo to a contact entry in Thunderbird fails to update in both the device or MPE.
ii) Adding a photo to a contact entry in MPE results in a successful update to the device but not to Thunderbird.
It appears this is not a new issue and for some reason photos in contacts presents a peculiarly tricky problem. Perhaps a work around might be to tailor the Thunderbird add-on to force an update in a similar manner to the Outlook one?
Contact photos not syncing to and from Thunderbird
Maybe this is the answer for your scenario i) http://www.fjsoft.at/forum/viewtopic.php?t=19805
Joachim
Joachim