Port can't find package macports?

[Malcolm Fitzgerald]

I've just upgraded from 10.3 to 10.4 and immediately prior to that I
upgraded MacPorts. 

The macports upgrade went smoothly and everything was working.
Following the OS upgrade I see this message when I try to sync or
upgrade. 

can't find package macports
    while executing
"package require macports"
    (file "/opt/local/bin/port" line 42)


malcolm