changing height - layout properties

Hi, this is my first post, managed to figure this software out pretty damn quick so congrats on the great software. My problem is I cant change the height and width of the layout, as soon as I change them it goes back to the default. Anyone know where im going wrong.

regards,

luke

<img src="http://wwweimagehosting/vpzst" border="0" />

freeimagehosting.net/vpzst

Get this error when I try straight from a new project

Answer here.