you can very easily take this tray out and give it a good clean. It's no doubt got blocked like mine did. Simply;
1. bend down to eye level with the tray and look to the back of it, on the top of the tray.
2. There's a red plastic lever which you push down on, and this releases the tray.
3. Pull the tray out while keeping the red lever down
4. Then the tray is easy to disassemble completely and wash thoroughly, where no doubt there is a blockage.
5. In addition, wash and scrub inside the washing machine, where the tray was - you'll also find a lot of gunk here.
Hope this helps.
Simon
February 2010