Odd window height and centered pixel perfect UI text issue

Hi.

When using a pixel perfectUI (all with point smoothing), everything works swell, fonts are nice and crisp. What is wrong is when the window height is not even.

Say at 600px it's working properly. At 601px the text is a bit blurry, at 602px it's good again.
Interesting thing is that bottom aligned "window" is not blurry at any resolution, only the middle one.

Other graphics work well too - as You can see the other pixel graphics are aligned properly and look good; it's only the text that gets blurry.

Is there a workaround to that?

Thanks,
Sivael