Please tell me if I'm being stupid !

I recently bought a 2002 (L322) 4.4 Vogue and have programmed my drivers seat in position "1". When I unlock the drivers door from the key fob (one press) the drivers seat stays in my position, but when I open all doors from the key fob (2 presses) the drivers seat moves into another position altogether !

Am I doing something wrong ?

put the key in the ignition [on] and set the memory button, i think this might solve the problem....

I had a similar problem with mine some time back, to solve the problem i used the memory seat set up procedure from the handbook but re did it for both keys as i found the other setting was from the second key and the memory setting was getting confused when i unlocked the car.
I also set the 2 keys the same but for a minor change to key 2 so the memory setting could see a difference.......not had an issue since.

The other thing you may need to do is disable the lazy seat which needs the dealer computer and lots of money