Centos – kernel source error on dahdi installation in centos

Trying to install dahdi from the link. I have downloaded package for dahdi. But on doing

cd /usr/src/dahdi-linux-complete*
make && make install && make config

My terminal shows

[root@localhost dahdi-linux-complete-2.10.0+2.10.0]# make
make -C linux all
make[1]: Entering directory `/usr/src/dahdi-linux-complete-2.10.0+2.10.0/linux'
make -C drivers/dahdi/firmware firmware-loaders
make[2]: Entering directory `/usr/src/dahdi-linux-complete-2.10.0+2.10.0/linux/drivers/dahdi/firmware'
make[2]: Leaving directory `/usr/src/dahdi-linux-complete-2.10.0+2.10.0/linux/drivers/dahdi/firmware'
You do not appear to have the sources for the 2.6.32-431.29.2.el6.x86_64 kernel installed.
make[1]: *** [modules] Error 1
make[1]: Leaving directory `/usr/src/dahdi-linux-complete-2.10.0+2.10.0/linux'
make: *** [all] Error 2

output of uname -r

[root@localhost dahdi-linux-complete-2.10.0+2.10.0]# uname -r
 2.6.32-431.29.2.el6.x86_64

I have the kernel source then why its showing the message
You do not appear to have the sources for the 2.6.32-431.29.2.el6.x86_64 kernel installed.

I know this question is asked many times.I have tried those but dint resolve this problem.
I have tryed updating my system but it says nothing to update.

Any Suggestions apart from reinstalling my OS???