I second that Andirez, When I started level design with UnrealEd I too used the stretch button thing.. but all it did was mess up my level which I had to redo every solid (blue) brush that I had stretched, the BAD effect was to have xmas-tree lights where the brushes meet. /infopop/emoticons/icon_frown.gif.
So as the man advised and IMHO build your geometry solid (blues) so its size is exact, ie. brushes that align to the grid, brush sizes which are exactly divisible by 2,4,8 etc etc, you don't want blue brushes of size 64.273373x159.37373x1010.283993, they may look on the grid... but they are not.
Semi's (pink) can be scaled by the way...
Bastard'O
P.S. Love the handle "White Rabbit", which white rabbit would that be...