Registry knots

[David Liontooth]

I modified a portfile by adding a tilde to the port name:

             transcode-1.1.0~cvs20070718

macports built the port, but got confused during the installation, so 
that now I get the cheerful

$ port installed
Error: port installed failed: Registry error: transcode 
@cvs20070718_0+a52dec+faac+freetype+imagemagick+libdv+libogg+libsdl+libtheora+libvorbis+libxml2+x264+xvid 
not registered as installed.
No ports are installed.

As you can see, it's truncated after the tilde, and then gone into 
knots. How can I untangle this?

It would not be a disaster to start afresh, but if there's a simple 
solution let me know.

Dave