google sketchup crashes on start

[ja5on]

Ello everyone

Doubt i'll get much joy but its worth a pop anyway.
For some reason when I try to run google sketchup (v6) it just spits the dummy with :

press ok and it does it again, click ok and it does nothing

I'm running XP with all the latest drivers for my gfx card, net framework etc etc

Its quite annoying as i really want to start designing my floating wall build

Does anyone know of any similar free software similar to google sketchup?

Thanks for looking