This sounds SO like Olivia. (She is now 3.5 and has grown out of it thank goodness!) but the "GO AWAY Mummy" thing happened A LOT from when she was 2 for a year.......)

I have no real solutions. I know it hurt my ego, and I got cranky inside thinking "Well bugger me love, I wish some days I could just leave you to your own devices" LOL (Obviously I never said that to her!)

The times that Olivia did it were on "school days" (childcare), which she loves.

Or on days when DH had looked after her most (ie I had been busy with Charlie or latterly Lexie)

Bec is probably right in thinking it is a toddler defence mechanism for a "punishment".

To avoid full on tantrums on exciting childcare I would get one of the childcare girls to help me get Charlie back out to the car whilst I took Olivia and we would all talk and get excited about what fruit was waiting in the car for her and what CD she could pick for the drive home. It didn't work every time, but it was a good enough distraction most of the time!

Good luck. I feel your frustration.....it is so hard when you love them so much and they appear to be so egotistically ungrateful!