Problem with Brush after installing Windows 7

[Diurno]

Hi all, i've just installed Windows 7, and now Photoshop cs4 act strange when using brushes, with every brush (not pencil i checked) the border is like this.... i tried to installa ps on my laptop that also has windows 7 and i've the same issue.... any help?

 

[Dezigns Unlimited]

Did you change the brushes hardness?

 

[Diurno]

Yeah, i've this sort of Noise only with a low hardness, here what i tried:

-reset preferences
-reinstall photoshop
-disable OpenGl drawing
-update video driver
-run photoshop in Windows Xp compatible mode
-change my monitor color management

All this stuff without any result.....