amavisd-new crashing

[Eric Sheesley]

For the past week or so I've had 2-3 different emails that, as they  
are attempting to be delivered end up crashing amavisd-new(just one  
instance, not the whole daemon) leading the the "error:  queue file  
write error" from postfix.  Both messages appear to have been 8bitmime  
encoded from a quick glance, but no other common points.  These emails  
will continually crash amavis every 15 minutes as the servers attempt  
delivery.  I've used portmanager to rebuild amavis and all  
dependencies with no change.  Any ideas on what could be wrong?