Hi again Here is some more info where the segfault happens. I compiled the code with -ggdb flags (as in the Makefile) (gdb) r Starting program: /soft/therion/loch/loch [Thread debugging using libthread_db enabled] [New Thread 0xb47bc710 (LWP 3705)] Program received signal SIGSEGV, Segmentation fault. [Switching to Thread 0xb47bc710 (LWP 3705)] 0xb59b0706 in glGenTextures () from /usr/lib/libGL.so.1 (gdb) bt #0 0xb59b0706 in glGenTextures () from /usr/lib/libGL.so.1 #1 0x080d28fa in lxGLCanvas (this=0x9465400, stp=0x9354270, dat=0x9350700, parent=0x9337398, id=-1, pos=@0x82c3ce0, size=@0x82c14f0, style=0, name=@0xbffd42c0) at lxGLCs.cxx:108 #2 0x080c0da7 in lxFrame (this=0x9337398, app=0x92e7538, title=@0xbffd4368, pos=@0xbffd436c, size=@0xbffd4374, style=541072960) at lxGUI.cxx:320 #3 0x080c159a in lxApp::OnInit (this=0x92e7538) at lxGUI.cxx:975 #4 0x080c8a00 in wxAppConsole::CallOnInit (this=0x92e7538) at /usr/include/wx-2.8/wx/app.h:76 #5 0xb77dff90 in wxEntry () from /usr/lib/libwx_baseu-2.8.so.0 #6 0xb77e01b7 in wxEntry () from /usr/lib/libwx_baseu-2.8.so.0 #7 0x080b6509 in main (argc=0, argv=0x0) at lxGUI.cxx:951 which must be line 108 in lxGLCs.cxx glgentextures(1, &this->m_idTexSurface); Since I have never programmed wx or glx stuff I would be glad to get some pointer how to proceed from here. Maybe this gives some more clues? (gdb) p &this->m_idTexSurface $2 = (GLuint *) 0xa02d5ac Thanks, Martin