compile error

http://forum.niosforum.com/work2/style_emoticons/<#EMO_DIR#>/sad.gif Hi,everyone.

When I build the software temple of simple Socket Sever in NiosII 5.0,it appears this error:

Please give me some advice .Thank you!!!!!!!!

make -s all

Compiling alt_lwip_fcntl.c...

In file included from /cygdrive/d/altera/kit/nio2v501/components/altera_hal/HAL/inc/sys/alt_sys_wrappers.h:48,

from /cygdrive/d/altera/kit/nio2v501/components/altera_lwip/UCOSII/src/alt_lwip_fcntl.c:55:

/cygdrive/d/altera/kit/nio2v501/bin/nios2-gnutools/H-i686-pc-cygwin/bin/../lib/gcc/nios2-elf/3.4.1/../../../../nios2-elf/include/sys/time.h:16: error: redefinition of `struct timeval&#39;

make[1]: *** [obj/alt_lwip_fcntl.o] Error 1

make: *** [system_project] Error 2