I had fitted the membranes over the winter having had substantial leaks on both doors as I had failed to fit the membranes during my rebuild.
But a couple of weeks ago we used the car for a long weekend to Dartmoor which included some rain. Although the main leaks seem to have gone, there was still water pooling on top of each sill right at the front end of the door opening an inch or so back from the A post where the bonnet catches are.
Today I had a closer look. As we know, there is a drip pan which is fitted on top of the front edge of the door where it hides under the base of the windscreen, which catches water which runs down the seal between the rear of the A pillar and the front edge of the door window frame, and which is drained down into the door cavity via a hole towards the front of the drip tray.
Well I found that on my (Robey replacement) new doors fitted by CMC, the drip tray is simply tack welded to the top of the door in about 3 places. There is a gap between the outer edge of the drip tray, and the upper surface of the door casing. Water collecting in the drip tray can run between the drip tray and the top of the inner door casing, from where it runs down the front of the door casing by the hinges and drips off the front of the door casing onto the sill!
I promptly used some seam sealer to fill this gap - I will paint over it once it has set.
Maybe worth taking a look at yours - it was easy to prove there was a problem by spraying water onto the door window/windscreen joint with the door closed. Open the door and watch the water escaping under the edge of the drip tray.