[PROBLEM] Samba don't work properly

[mapomme1108]

Hello,

I use Xbian 1 beta 2

I want to connect to my home made NAS (which is running Windows 7 Home Premium x32)
At first it works but then the connexion is impossible. The error message is : "connection timed out"

While I have this error, it is still possible to connect my Windows 8.1 notebook from the pi and I can connect to my NAS from my notebook

Is it a known issue?

Thanks per advance for your help