I cleaned the drawer and all of its parts many times, even putting it all in the dishwasher but this made no difference. It turned out that the drawer was not the problem. The water holes above the drawer were blocked. I removed the drawer and sprayed lime lite and used a little jewellry cleaner brush (A toothbrush would do) to give a good scrub to the whole roof area of the drawer unit. Rinsed with a cloth and clean water. This worked a treat it is all working ok now. I have bought a washing machine descaler now which I will use on a regualr basis. Hope this works for you.
Liz
June 2012