invalid command name on some downloads

[Barry McInnes]

We have a clean install of 10.5 and update to 10.5.1.
macport version
[mac27:~/sun/info] bmcinnes% port --version
MacPorts 1.520

Some installs work, others don't

[mac27:~/sun/info] bmcinnes% sudo port uninstall gimp
Error: port uninstall failed: Registry error: gimp not registered as
installed.
[mac27:~/sun/info] bmcinnes% sudo port install gimp2
Error: Unable to execute port: invalid command name "destroot.violate_mtree"
[mac27:~/sun/info] bmcinnes% sudo port install gnuplot
Password:
Error: Unable to execute port: invalid command name "destroot.violate_mtree"
[mac27:~/sun/info] bmcinnes%

I have reinstalled Xcode 3.0, done port sync, looked through archives,
but there seems to be no total solution ?