AMDS problem with AFS3.4a

[Bob Dew]

Since upgrading our Sun AFS servers to AFS 3.4a (+patches), Sun client
machines (running AFS 3.3) experience intermittent problems reading and
deleting mail via AMDS.  The "messages" application reports, 

Error: No more processes (in flock in OpenMSDirectory)

Has anybody else seen this or know what to do about it?