I installed the Joomla Modul mod_AddThis in my Joomla 1.7 successfully.
But if I choose the "TOOLBOX" mode and enter some services like
Toolbox services: facebook,email,google,gmail
Size 32px - and apply
(while using addThis default CSS)
..then other icons are shown from Addthis (always the same icons, just the amount differs) like: email,stumbleupon... (4 icons at all)