Mira Aquations

If it is dripping from the shower head then it is likely that the flow cartridge is passing and this will need replaced.

http://www.showerdoc.com/MIRA-441-56-Mira-Flow-Cartridge-Assembly-441-56

A new cartridge may help this.

However the problem will probably be caused by unequal pressures normally the cold being a higher pressure than the hot.

It would be worth while checking that the filters are clean and the check valves are working properly.

Have you checked that the inlet filters and check valves are clean?

http://www.showerdoc.com/shower-spares/mira/MIRA-PARENT-90-Mira-Aquations