[Inkscape-user] problems with curves

hi all

i'm working on graphics, for wich i need a clipart of a monitor. because i couldn't find any nice perstective pics of monitor, i draw some. they are not very nice, but work for me. exept that i can't resize them, because they get all mangled up. how come? isn't vector graphics all about lossless transformations?

i attached the file, with original, not resized drawing.

i need these for a flyer i'm creating in scribus. i'd really find useful any advice. otherwise, i'll have to use png exported pics...

regards, bostjan spetic