[ubuntu-za] Thunderbird behavior

[Jan]

Good day all,

Thunderbird Mail is behaving in a strange way on my Ubuntu 16.04 Unity 
installation. The problem appears to have started with recent updates.

When Thunderbird opens automatically via Startup Apps, the text beside 
the icons (Send, Spelling, Attach, Security and Save) in the composition 
toolbar does not show. If I restart Thunderbird manually, the text 
re-appears.

I have re-installed the Thunderbird packages via Synaptic, have added 
packages in Synaptic that I thought could help, deleted the localstore 
folders (http://kb.mozillazine.org/Localstore.rdf) but nothing seems to 
resolve this issue, except a reboot of the app.

Any suggestions, please?

Kind regards,

Jan