I hope someone can help with this, it is driving me nuts!
I have just upgraded from A5 to A7extra. When I add an object in WED, it is displayed ok(bright red) but after I select it or do anything, for example maximise one of the windows, it goes a very light colour which is almost imposible to see and modify. Never had a problem with this in A5.
Upgraded my graphics driver and all Vista updates.

try disabling aero

Sorry but where do I find this option?

Go to "MED.exe" -> Right-Click and go to "Properties" -> Go to "Compatibility" tab -> Check "Disable desktop composition".

Still does the same thing!

Can you post a screenshot?

Now something realy strange is happening, I did a screen capture and tried to save it in ms paint but the display problem did not show up when it was pasted into paint. I have re downloaded and installed Game studio, double checked my display driver. Opened A5 to see if there is a problem in that but no problem there.
I am running it on a laptop if that is any help.
It's just bloody anoyinh because it is impossible to use and feel that I have wasted my money.

Have you tried changing the WED video-out drivers at all?
WED - File - Preferences - View Options - Video Out (icon)
Ive had the best luck on multiple machines with the Dx9a "pair".

Also, make sure youve got a healthy and up to date DirectX 9C.
(test a real game to check DX's health)

I will have a play about on Tuesday, off to bed now!

Great, changed to Dx9a "pair" this sorted out the 2d views but made the 3d view colours go strange when selected. So I did the 2d as dx9a and the 3d as dx9 and this has sorted the problem.
Thank you so much for your help.