I have a Hotpoint TDC60 and the filter is nearly always wet?

I have Hotpoint TDC60 tumble dryer with a consistently wet filter. I clean both the filters regulary (one in the door and one underneath the door) and empty the water tray out after each load. However i'm finding the clothes only tumble for maybe one complete load and by the second load the large filter is wet and needs to be dryed out fully before the clothes will dry again. I would appreciate any ideas, i have had this tumble for many years and it has never let me down before.

Tracey
January 2014