OK, an update on this issue.
I have recently bought a handful of KONIG DiSEqC Switches 2.0 part no. SAT-SWITCH11W from ebay. They are two way.
I have two cables coming in, one from my Motorised dish(TM2200) and one from the Freesat/Sky/28E minidish. I have connected the diseqc switch with 28E fixed going to input 2 and the motorised going to input 1.
Now.
With my TM600 Linux machine everthing works faultlessly; instant switching to 28E, and when I selec another sat, the motor goes round and works OK too.
But.
With my TM5400CI+ USB super, it does not work properly.
With all sats set to Diseqc 1.0 port 1 the motor moves fine, and I get all sats. But when I set 28E to use port 2, the motor no longer works, but I do get 28E from the fixed dish. So it kind of half works, but you have to mess with the diseqc 1.0 settings for 28E only when you wnat to switch between motorised and fixed.
So.
I think I'll stick with the Linux box for the moment.
On the Linux machine, setting up for motorised and fixed was pretty easy, I simply went into the satellite setup menu and changed the diseqc switch setting to use the 2nd port for 28E.
If I remember correctly, the 'many satellites via a motor' option then changed automaticallly to custom setup.