Error verifying signatures...

We're running about 12 machines with redhat 8, and Ximian Desktop 2. 
Just recently I've been getting the following error on all of them when
trying to run updates.  They actually do it for all packages, this one
just happens to be openssh..  I've tried unchecking require signatures,
as well as disabling the cache also provides no fix..

Transaction failed:
Couldn't verify
signatures: couldn't prepare package
signature: unable to read from
/var/cache/redcarpet/packages/openssh-server-3.4p1-7.i386.rpm:
unable to read package header

-mike