another vote for the eno.

i know a guy who is an amaizing AL welder who has the capability to do it. but even so i still would'nt do it especially with an older canondale that has already been stressed for years the welding and second heat treating (if required, depends on the type of Al used in canondale frames) will only make the frame more prone to failure. get an eno or get a new frame. hyperrevue just picked up a canondale track frame for 300 so they are out there and not too expensive.