Display problems with downscaling using 1.0.0-rc2

[dany99]

I used rc1 before, this problem did not appear. I am using Microsoft Vista.

When I watch a movie or tv (I tried with divx and sap service), vertical and horizontal lines appear on the video. These lines are more visible while displaying a downsized image, but they sometimes remain with a zoom of 100% or a little more.
Strange artefact may be seen with smaller zooms. Both artefact and lines cannot be seen in full screen mode.

Edit: Adding OS

[dany99]

This problem disappeared with rc3.