[Cooker] su: could not open session

[Bryan Paxton]

After an upgrade last night(NOTE: I really need to make note of the
packages that I upgrade during a mass upgrade), I get this error as _root_
when trying to su. As a normal user I get incorrect password and it
doesn't even give me a chance to enter a password, just spits out the
error. 

The only thing I could think this is caused from is a pam problem, but I
can't validate this. 
Any clue ?

--
Bryan Paxton