Screen redraw with sandbox

Avast Free Antivirus / Premium Security
1

I run browser, FF or IE9, in the sandbox always.
I notice that if I drag the browser window around the desktop (icons) need to redraw.
If I run the browser without sandbox it does not happen

2

First I must make sure I got your complaint… when you run IE/FF sandboxed and you move this applications above desktop’s icons - then are they visibly redrew? or is IE/FF visibly redraw? (e.g. blinking?). Do you use Vista Aero, right?

Thanks.

3

I do not use Aero at all.
Trying this again I think you are correct that it is IE/FF that are slow to redraw and this gives the impression that it is the icons being redrawn.
I can see the ‘ghost’ of the browser being ‘left behind’