not going to mid position on valve?

when I replaced the actuator on the mid position valve and controler I found that I could get heating and i could get hot water
but not both at the same time.
I have found that if I want hot water there should be 240v going to the orange wire. (which I do)
if I want heating I should have 0v on the orange wire and 240 on the white and 240v on the grey.(which I do)
I have also found out that if I want the mid position valve to go to the mid position I should get 240v on the orange and 240v on the white, which by some jiggery pokery puts it into the mid position.(which I get)

now this is where it all goes a bit pear shaped.
even though I do get the 240v on the orange and 240v on the white which should put it into the mid position it does not and now I am baffeled.

I have a drayton tempus 7 programmer, and a ACL lifestyle (drayton) mid position valve actuator.
I have the programmer set up for a pumped system as I have a pump.
the wiring goes as follows to the 12 way junction box
N-2 L-1 1-8 2- 3-6 4-4 as per the wiring diagram.

I have the actuator set up as follows to the 12 way junction
W-5 GR-8 OR-7 BL-2 YG-3 as per the wiring diagram.

so wired like this should put it into the mid position and control the heating via the room stat and the hot water via the cylinder stat.

so what have I done wrong? I think it was when I replaced the actuator and have not set it up corectly but not sure?

Antony
November 2008