I also got the message kpdf: ../../src/xcb_lock.c:33: _XCBUnlockDisplay: Försäkran "xcb_get_request_sent(dpy->xcb->connection) == dpy->request" falsk. That is when running with command line kpdf /tmp/cc2400.pdf but running in debug mode with gdb goes fine! The file I am trying to open is called cc2400.pdf and has md5 checksum 6975ac1bbcb2ff50371acfd3c80f6d0f It is available at http://www.ti.com/lit/gpn/cc2400 paul