X2 Disappearing ProChannel modules

Suddenly my Channel Console Emulator is not listed for insertion.
Bus Console Emulator is there OK. Bth DLLs are in place in Shared Utilities/Internal.
I say "suddenly" because it was there - I copied Craig Anderton's multi-insertion technique with success.
But now it's gone and my R-Mix and PC4K-S Bus Compressor aren't listed either... nor are they in Shared Utilities/Internal.
I've installed X2 again but no joy.
Anyone know what's going on?
Thanks.