Moode eventually unrechable until i reboot...

[vinnn]

Possibly a bad/corrupt SD card or an insufficient power supply?
When you say "unreachable", what is unreachable? Is it just the web interface or does the Pi not respond on the network when pinging or attempting an ssh connection?
Also when you say "reboot" what do you mean? Are you logging in and running 'sudo reboot' or yanking the power cable?