Powder drawer will not go in?

I have a Whirlpool washing machine AW/M 5104/4 and this morning after the powder drawer was thoroughly cleaned it will not go all the way back in to the slot.
I have looked in the slot and there are no obvious obstructions but I do see a small pipe way at the back that resembles the top of a sealant tube.This is capable of being moved using a long flat screwdriver and appears to be on a sping as it moves too the righ but then clicks back to the left where I think it is stopping te frawer from going in fully. Any suggestions?

Gerry
June 2012