Can't compile - trouble with glib

[V Spagnolo]

I thought I would install 2.2.9 on Ubuntu 9.04 and am now stuck.

My first attempt to make 2.2.9 resulted in:
    checking for GLIB - version >= 2.6.0... no
    configure: error:
    *** GLIB >= 2.6 is required to build Gnucash; please make sure you
have the
    *** development headers installed. The latest version of GLIB is
    *** always available at ftp://ftp.gnome.org/pub/gnome/sources/glib/.

So, I got glib 2.9.6, installed and tried ./config again. Now I have:
    checking for GLIB - version >= 2.6.0...
    *** 'pkg-config --modversion glib-2.0' returned 2.9.6, but GLIB (2.20.1)
    *** was found! If pkg-config was correct, then it is best
    *** to remove the old version of GLib. You may also be able to fix
the error
    *** by modifying your LD_LIBRARY_PATH enviroment variable, or by editing
    *** /etc/ld.so.conf. Make sure you have run ldconfig if that is
    *** required on your system.
    *** If pkg-config was wrong, set the environment variable
PKG_CONFIG_PATH
    *** to point to the correct configuration files


Advice please. It has been a very long time since I mucked around like this.