Mike and Exit, thats interesting because the other night i had to make an 8 inch square cake for an anniverary cake for today, usual mix, usual method, for me anyway (creaming method) and normally they turn out fine, but i got abit stressed as i attempted to cook also( fish pie) the only thing i can think off i did was to stop my mixer after i creamed the butter and sugar for few mins to do something else, then carried on as normal, well the dame thing sunk before my eyes, so mortified i started again, time was against me so i bunged everything in and mixed for few mins put it in the oven and it was bloody fine.
So my question is, was it due to the fact i stopped the mixer even though it was all nice and fluffy? My nitemare didnt end there though, i had some buttercream left over with some creamcheese in it and put it in my sponge and for the crumb coat, all fine i thought untill i came to cover it in fondant, no no no, will never do it again as the fondant was wet, shiny, and very very sticky, was not happy, didnt know what to do so the only thing was to see if it would dry over night, thankfully it did but it was touch and go, the moral of this story is i found out later dont put creamcheese in your frosting as apparently it dissolves the icing, lesson learned for me i'm afraid.