It helps if you provide the correct URL for the screenshot...
http://dl-web.dropbox.com/u/4558613/gnustep_ui.png
Looking at the picture, it seems that the images that are rendered are in the
wrong place, so possibly this is an issue with flipped vs non-flipped views, so
the images in the buttons are being rendered but not within the controls'
bounds and so are outside the clipping region and are missing.
Which back end are you using? The text antialiasing looks like libart, which
possibly isn't well tested with the most recent changes to the flipped view
support.