cross compile qt will not run var directfb

I have cross compiled qt but It can not run with directfb ,
when I run program with "-qws -display directfb" , It display the following

~~~~~~~~~~~~~~~~~~~~~~~~~_{| DirectFB 1.4.3 |}~~~~~~~~~~~~~~~~~~~~~~~~~
(c) 2001-2009 The world wide DirectFB Open Source Community
(c) 2000-2004 Convergence (integrated media) GmbH
----------------------------------------------------------------

driver_open_device 0 -------------wfwfwffwf--------
[ 1684: 0.000] -> Caught signal 11 (at 0x1c, invalid address) <-

But My directfb is good , if I run directfb program(such as df_dok ...) not var qt , it can run ;