[Insight-users] Error running Geodesic example under InsightApplicaiton

[Yang Wang]

Hi, Luiz and Itk/fltk user,

I have successfully compiled itk/vtk/fltk/itkapplication under Red Hat 
Linux,
and tried to run "Geodesic Active Contour Segmentation" under the
InsightApplication directory.

The fltk GUI is shown correctly, i tried to load the 3D image
"BrainProtonDensity3Slices.mha" under /Insight/Examples/Data/,
and used the "Display" botton besides "Clear Seeds", it displayed correctly,
however, when I tried to press the "Gradient Magnitude" button,
the program exited and a warning message appeared in the command line,
"Xlib: extension "XFree86-DRI" missing on display ":0.0". Aborted".

Can you tell me what is going wrong? I even tried with 2D images and
different settings of the value for "Sigma", the warning messages were 
still there.

Thanks.

Casper