determining which package is 'responsible' for forcing a downgrade ?

[Gustavo Niemeyer]

> it seems to me that smart should NOT be trying to 'upgrade' my
> MozillaThunderbird anyway, as what's _installed_ is (a) the latest
> available version and, (b) in the highest priority repo anyway.

It looks to me like there's an "obsoletes" relation there. Can you
please run the command "smart query --show-all" on your installed
package to see what it will tell us?

-- 
Gustavo Niemeyer
http://niemeyer.net