hostapd 0.7.3. : problem : deauthenticated due to inactivity

[ph35sm at free.fr]

Hi again,

After reviewing events I can say : 
- Wifi stop functionning on 09/07 around 11:30PM without any action from me.
- On 09/08 morning I see that wifi doesn't run anyway.
- Stop hostap, deconfigure interface, reconfigure network, restart hostap : no lucky still not running,
- Update system and reboot 
- Wifi still not running

Is anybody can help and suggest me something ?
thanks
P.