Compiling ROOT 5.27 in ubuntu 10.04

Hi,

I've had this problem compiling ROOT in ubuntu since ROOT 5.26 and ubuntu 9.10. When I compile I get the error:
"Checking for libX11 ... no
configure: libX11 MUST be installed"

• Checking the synaptic package manager libx11-dev, libxpm-dev, libxft-dev, libxext-dev are all installed and reinstalling makes no difference.
• sudo apt-get install xorg-dev tells me xorg-dev is already the newest version.
• ls -al /usr/lib/libX11* :
  -rw-r--r-- 1 root root 1700216 2010-02-03 22:06 libX11.a
  lrwxrwxrwx 1 root root 15 2010-05-30 12:27 libX11.so -> libX11.so.6.3.0 lrwxrwxrwx 1 root root 15 2010-05-29 22:22 libX11.so.6 -> libX11.so.6.3.0
  -rw-r--r-- 1 root root 1160008 2010-02-03 22:06 libX11.so.6.3.0
  

These are all the possible solutions I have found but none of them work. Is there something else missing? The configure command I use is given below.

Best Regards,
Sinéad

./configure linuxx8664gcc --enable-asimage --enable-astiff


--enable-exceptions --enable-krb5 --enable-ldap --enable-opengl

--enable-pythia6 --enable-pythia8 --enable-qt --enable-genvector

--enable-fftw3 --enable-afs --enable-python --enable-roofit

--enable-shadowpw --enable-ssl --enable-xml --enable-minuit2 --enable-unuran