running gtkada under gps

Running a gtkada application from gps, I get the following messages :

relocation error: /usr/gps/lib/libgtkada-2.4.so.0: undefined symbol: 
__gnat_eh_personality
process exited with status 127

when running Build -> Run... and

Program exited with code 0177.

when running from the debugger

When lauched from a shell, the application works fine (as it always 
did...). The same happens with other appgtkadfa applications

Perhaps it come from the fact there are 2 libgtkada-2.4.so.0 : one 
coming with gps, one coming with gtkada, and it seems they are different.

Did I do something wrong when installing gps or gtkada?

Thanks for advice

AL