Portmanager gives me an error message

[Eduardo Cerejo]

I'm trying to upgrade any port with portmanager because portupgrade keeps failing all the time.  No matter what port I try to upgrade I get this error:

sudo portmanager x11/xterm -l -u
Password:
MGrStrlen error: NULL marker not found in string
Assertion failed: (0), function MGrStrlen, file MGrStrlen.c, line 54.
Abort

I'm running FreeBSD 7.1 release.