On ubuntu 10.04 cannot find "libpyglib-2.0-python.so.0"

Gentleman,

I've installed GNAT-GPS downloaded right now from main website. I 
followed all installation instructions provided in README but when I 
starts GPS with "gps_exe" from command line this is the result:

Traceback (most recent call last):
   File "<stdin>", line 1, in <module>
   File 
"/cardhu.b/gnatmail/gcc-43/install-cardhu/python/lib/python2.5/site-packages/gtk-2.0/gtk/__init__.py", 
line 38, in <module>
   File 
"/cardhu.b/gnatmail/gcc-43/install-cardhu/python/lib/python2.5/site-packages/gtk-2.0/gobject/__init__.py", 
line 26, in <module>
   File 
"/cardhu.b/gnatmail/gcc-43/install-cardhu/python/lib/python2.5/site-packages/gtk-2.0/glib/__init__.py", 
line 22, in <module>
ImportError: libpyglib-2.0-python.so.0: impossibile aprire il file 
oggetto condiviso: Nessun file o directory

(I've installed an ubuntu with italian language pack - last line means: 
"Unable to open shared object: no such file o directory")

I've verified that such library exists in /usr/gnat/lib together with 
some links:

lrwxrwxrwx 1 fpiraneo fpiraneo      29 2010-09-15 13:29 
libpyglib-2.0-python.so -> libpyglib-2.0-python.so.0.0.0*
lrwxrwxrwx 1 fpiraneo fpiraneo      29 2010-09-15 13:29 
libpyglib-2.0-python.so.0 -> libpyglib-2.0-python.so.0.0.0*
-rwxr-xr-x 1 fpiraneo fpiraneo   31945 2009-12-16 07:43 
libpyglib-2.0-python.so.0.0.0*

The PATH is set to:

/usr/gnat/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games

I tried also an installation from ubuntu repo with the same results.
I have another problem that I don't know if it's related with the 
library: when I create a new ADA project and I insert the main source 
adb file, this file is not shown on the left project tree (and obviously 
it doesn't compile because it's unable to find the sources); same 
problem when I manually insert the source name on the project source file.

Just to test my own operations I tried everything on a WinXP virtual 
machine and everything works fine.

Any clue will be appreciated.

Thank you very much and have a great day.
Francesco Piraneo G.