[Buildroot] error about compile gcc

[loody]

Dear all:
I use buildroot to build mipsel toolchain and I got the error message below:
/media/sda6/uclinux/toolchain/mips/temp/buildroot-2009.05/build_mipsel/staging_dir/usr/include/unistd.h:243:
error: two or more data types in declaration specifiers

I have google the error
message,http://osdir.com/ml/lib.uclibc.buildroot/2007-06/msg00076.html,
 but the error still exist even I use "--disable-libmudflap ".

My buildroot version is 2009.05, Released June 1st, 2009
If someone has the same error as me before, please let me know.
appreciate your help,
miloody