Electric seat and electric mirrors confused

On my 1993 RR, when I use the driver's seat fore & aft adjuster switch, both the left and right mirror motors are activated to move both mirrors 'in' and 'out'. When I use the driver's seat backrest angle adjuster, the left mirror is adjusted 'up' and 'down'. The seat adjustment doesn't change. The mirrors can still be adjusted using the appropriate dash-mounted selector and joystick. The passenger seat controls work as they should. Any suggestions how such separate devices can get to be confused? (This is a right hand drive UK spec vehicle).

Hi
I have listed the same problem on my LSE in the last couple of weeks but have had no reply. The only differance is that my mirrors would not work on the dashboard switch before.

Thanks Craig

I suppose I have already assumed that there's a processor (under the driver's seat) that memorises positions of both the seat and the mirrors. If my experience of boards in washing machines and stuff is any guide, there might simply be a smoke-based bridge between circuits, consequent on overheating or whatever. I have fixed faults by cleaning such bridges with a meths-laden q-tip. But is there such a processor, is it under the driver's seat (I can see hardware in there) and how can it be accessed?