So this has been a very irritating problem for a while now.

If you drive in dry weather it never happens.

Just drive in the rain and within a 100km or so, you feel the car start to slow down gradually, eventually its so slow that then the car has to be stopped as the brakes lock themselves completely.

Turn the car off for a minute or two, pump the brakes and it lets go again.
Just weird.

Any suggestions???