MySQL local connection Problem

[BenjZ]

Hello,

Today I encountered a strange problem while trying to connect to my MySQL database on my redhat linux server:
- all connections made from mysql command-line client are fully fonctionnal,
- all connections made from another computer are ok,
- BUT, all connections made from the computer on which MySQL is installed, from home-made c++ software (with mysql standard library) DON'T WORK, whereas yesterday all worked without problem !

I don't understand what's happening, I tried to reboot server but it does the same...

Does someone have an idea?

Thanks a lot for your help!!

Benj