
Not so long ago I brought a Renault Megane 1.9dci 120 dynamic estate. I've treated it to a cambelt change and full service and up until Monday it has been virtually fault free.
Monday afternoon, the weather is sunny so I decide to wash the car with my 3 year old son keen to help. Whilst I vacumed and cleaned the inside he was sat on the drivers seat pretending to drive the car and pressing all the buttons he could reach. The key was safely in my pocket so I didn't think he could do any damage.
A couple of hours later and the car is gleaming inside and out. I've turned the lights off and the neighbours are glad the horn isn't blasting away every few seconds!
Since owning the car I've always started it by depressing the clutch pedal whilst pressing the starter button, but since cleaning it, it will only start now when the break pedal is depressed and then not always first time (especially when cold). Even when starting the car in gear I have to depress both clutch and brake pedal.
Has anyone got any ideas what has happened and how to cure it? (And is my son to blame or my enthusiatic buckloads of water?)

Many thanks