usetex font problem

            s+='latex font: %s %s'%

    > (rcParams['font.latex.package'], rcParams[''])

    > So it should not be necessary to clear your tex.cache.

Oops, I also added the to the Agg key

Checking in lib/matplotlib/backends/;
new revision: 1.42; previous revision: 1.41

It would be useful to centralize the cache key generation, since it is
fragile to have texmanager and backend_agg doing this