Receive error when i try to portmanager -u

When I run portmanager -u, I receive the following errors:

------------------------------------------------------------------------
portmanager 0.4.1_9: Collecting installed port data
------------------------------------------------------------------------
2 open conditionals:
           at line 1131 (evaluated to true)
          at line 1131 (evaluated to true)
make: fatal errors encountered -- cannot continue
MGdbAdd error: attempt to place null data into record halted
Assertion failed: (0), function MGdbAdd, file MGdbAdd.c, line 78.
Abort (core dumped)

Sol: problem seems to have been resolved by 
re-building the ports tree. I did a 'portsnap extract' instead of the 
usual 'portsnap update'.