[Cooker] problem with rpm: cannot open database

[David Aspinall]

Has anyone noticed an weird problem using the rpm command in quick
succession to upgrade packages?  I occasionally get the spurious error
"cannot open database" between commands.

This wasn't a problem until I started using autorpm to upgrade cooker
rpms automatically from a local mirror directory.  It keeps crashing
part way through with "ERROR: RPM cannot open RPM database..."

This happens with rpm-3.0.3-43mdk from M7 as well as current
rpm-3.0.4-0.12mdk

rpm bug?  anything else it could be?

 - David