Indesit WIDL126 -won't take fabric softener during cycle?

I recently cleaned the soap drawer in my washer/drier and ever since, it's not taken the fabric softener fluid down during a cycle. The washing liquid goes down fine but the fabric softener just sits in the tray until the end and is defiantly still there at the end of the cycle! I can't work out what has gone wrong as it was fine before I cleaned it! I can't see any obstructions, my husband has double checked that I've not done anything wrong (what could possibly go wrong, it's so simple to get the drawer out!). Can anyone suggest anything please, I'm desperate!