Tectia is using QT library and in this case there is an issue in this QT library component. This issue will garble the fonts in certain cases.
For more information, please see the QT library's problem report about the issue: http://bugreports.qt.nokia.com/browse/QTBUG-7572
To fix the font corruption problem, please do the following steps:
1) Open the registry editor (Start menu -> "regedit")
2) Navigate to registry key:
3) set "FontSmoothingGamma" to 700 (decimal value)
3) logon again and now fonts can be seen normally
If the "FontSmoothingGamma" has too high value it will cause the corruption effect.
Please notice that in the future, you will need to perform the same recovery steps again if the value is set back to the original (too high) value by other programs (this could happen i.e. after system restart).