The most likely cause is overfixing.  Try about 1/10th the amount of
fixer usually used (24g sodium thiosulfate per liter).  Also, don't fix
longer than two minutes.
> Also sometimes I get irregular spots in the emulsion (sort of like a water mark)
> which I think could be where the paper ripples during drying and  some of the
> emulsion puddles up.  Do you think this is what it could be or some other
> problem.
How old is the sensitizer?  If it's more than half a year old it "could"
be going bad.  Also, if there's any puddling, I'd suggest that you are
using too much.  A thin coat is best anyway, as the thicker coats will
lose a bit of contrast.
 
Cheers -
george
-- Handmade Photographic Images http://www2.ari.net/glsmyth/