I have a simple LANC controller (SignVideo) that works fine with my Sony VX-2000 and VX-2100 but won't work with my A1.

Help?

You need to isolate the problem -- it's either with the controller or the camera. If at all possible, try to get your hands on another LANC controller. If it works, then it's just a compatibility issue. If it doesn't work, then it's a service call to Canon.