Evolution not learning junk

[David Niemi]

With FC3 every week or so Evolution would "learn Junk" then expunge it
but my FC4 install isn't.  I'd copied all of my evolution files from
the .evolution directory from FC3 to the FC4 install and I am not sure
if this created the problem

My Junk folder is getting quite full ~700 messages and I'd like to fix
this, any suggestions?  I couldn't find much of any use with Google.