I have just had the same problem with my Bosch 4030. I cleaned the filter and it is now working better than it has for a long time. Just watch out for the amount of water that will empty from the filter area. Have plenty of towels to hand. Once I released the filter slightly the machine started emptying immediately. Turns out it was a small piece of metal that caused the problem.
Hope this helps
Doreen
March 2009