Unreadable text with certain Cleartype settings

The following problem was reported by some of our users (diffrent company / Windows installations):

With some Windows Cleartype settings, every Qt drawn text become unreadable. This include QTextEdit, QLabel, QWebView, etc.
See the attached picture for examples.

The Fowollings settings are activated on some the problematic computers:
[HKEY_CURRENT_USER\Control Panel\Desktop]
FontSmoothing="2"
FontSmoothingGamma=0x84000000
FontSmoothingOrientation=0x1
FontSmoothingType=0x2

You must logout from your windows account to activate theses settings