wifi goes down after a while

[QuadCorei8085]

@rasmonski: have you made any progress?

found a topic regarding power management:
http://www.raspberrypi.org/forums/viewtopic.php?f=45&t=46569

I will try and report if this solves the issue or not, although I dont think that this could give us (me) the solution since
in my case the PI is showing "inet addr: 192.168.1.120" when I'm unable to ping it from external source or ping the router from it.

Seems that I'm facing the same problem:
http://raspberrypi.stackexchange.com/questions/13473/connected-to-internet-but-cant-ssh-or-ping

As it is dated with current year, feb it looks like something changed either in debian or xbian.