Greetings,
After this ticket (http://bugs.freedesktop.org/show_bug.cgi?id=24516) was solved, I managed to successfully compile radeonhd driver disabling dri extension.
Then I tried to enable it, and this time I had this compile error:

rhd_biosscratch.c:47:39: error: X11/extensions/dpmsconst.h: No such file or directory
rhd_biosscratch.c: In function 'RHDAtomBIOSScratchPMState':
rhd_biosscratch.c:553: error: 'DPMSModeOn' undeclared (first use in this function)
rhd_biosscratch.c:553: error: (Each undeclared identifier is reported only once
rhd_biosscratch.c:553: error: for each function it appears in.)
rhd_biosscratch.c:556: error: 'DPMSModeStandby' undeclared (first use in this function)
rhd_biosscratch.c:557: error: 'DPMSModeSuspend' undeclared (first use in this function)
rhd_biosscratch.c:558: error: 'DPMSModeOff' undeclared (first use in this function)
make[3]: *** [radeonhd_drv_la-rhd_biosscratch.lo] Error 1
make[2]: *** [all] Error 2
make[1]: *** [all-recursive] Error 1
make: *** [all] Error 2

Here I put once again some information about my building environement:

Here is my uname -r:
2.6.24-24-generic

My gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v
--enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr
--enable-shared --with-system-zlib --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --enable-nls
--with-gxx-include-dir=/usr/include/c++/4.2 --program-suffix=-4.2
--enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr
--enable-targets=all --enable-checking=release --build=i486-linux-gnu
--host=i486-linux-gnu --target=i486-linux-gnu
Thread model: posix
gcc version 4.2.4 (Ubuntu 4.2.4-1ubuntu4)

I hope You have enough information, have a nice Day.