Omega brakes bind in wet weather

New pads and discs fitted at front, Checked rear pads and cleaned rust off
calipers and pad retaining pins,cleaned rust off front calipers, calipers
moving freeley, pistons retract ok.

In dry weather no problem noticeable but in damp or wet weather I can feel
the car holding back and the brake pedal is hard and only needs slight
application to stop car.

I did notice when removing old front pads and fitting new ones that three of
them just slipped in and out but one seemed to be catching slightly and
needed tapped into place, this was the same with the old pads as well.

When the weather is dry the discs get hot all round but when it is wet and
the holding back is noticeable they are hot enough to burn fingers.

Any ideas would be greatly appreciated.