Install problem with GTK+.

[hellokitty e-box dk]

First of all, greetings to all of you. :)

To the problem.
In the directory, gtk+-2.2.4 I did the following:

PKG_CONFIG=/usr/local/bin /* pkg-config executable is here for sure */
export PKG_CONFIG
PKG_CONFIG_PATH=/usr/lib /* Not very sure whether the libraries are here!
*/
export PKG_CONFIG_PATH

./configure --prefix=/usr/local

Installing pkg-config 0.15.0 before configuring GTK went fine:
./configure --prefix=/usr/local
make
make install

However, when configuring GTK+2.2.4 I get the following error message:

*** Your version of pkg-config is too old. You need version 0.9.0 or newer.
*** See http://www.freedesktop.org/software/pkgconfig
configure: error: Library requirements (glib-2.0 >= 2.1.4 atk >= 1.0.1 pango
>= 1.0.1) not met; consider adjusting the PKG_CONFIG_PATH environment variable
if your libraries are in a nonstandard prefix so pkg-config can find them.

Question A) Why does it complain about pkg-config being too old? I set the
environment variable PKG_CONFIG to /usr/local/bin where pkg-config is located.
Doing:

jack linux:/usr/local/bin> pkg-config --version
0.15.0

... confirms my version number (strangely, I cannot call pkg-config from
other directories).

Question B) The configure error message prompts me to set the PKG_CONFIG_PATH
env var which I've done as shown earlier on. I must admit I'm not very sure
whether the libraries are there though. How can I know for sure? Perhaps
one can give me a pkg-config library file which I can search for?

Thanks in advance. :)