Hi Everybody.

I have a laptop with lubuntu 12.04 installed.
My problem is that when lubuntu has started and wireless connection has been established then after a while I received no replied doing ping to this laptop (from a ubuntu PC or Windows XP PC)
Amazingly, if from the laptop I first ping to one of the other machines then the laptop replies correctly to the ping of the machine that previously has been pinged.

Any idea?