gdb signaled SIGSEGV while loading a program

Hi,
This my directory tree:
~/src
|_DataServer
| |_DataServer
| | |nto
| | |
etc.
| |
| |_DataServer_API
| | |nto
| | |
etc.
| |
| |_test
| | |nto
| | |
etc.


I go to my project directory
$cd ~/src/DataServer

Now I launch pdb for the DataServer:
$pdb ./DataServer/nto/x86/o.g/DataServer_g

Everything is OK.
I exit pdb and I try to launch it for test
$pdb ./test/nto/x86/o.g/test_g

It displayed a dialog box saying that gdb is signaled SIGSEGV.

If I do like that:
$cd ./test
$pdb ./nto/x86/o.g/test_g

It’s OK.
Why do I have to go to ./test ?
Why it was not necessary for DataServer application?

Thanks,
Alain.