Don't bother, seems to me that the problem was a cordless phone station placed nearby router. I've set the channel to 11 and everything started working.
I have Asus wl-500g and a wl-107g. Occasionally, my connection drops, and I can't figure it out why. If I search for available wireless networks, none is found. After a few hours, things magically start working again. I don't know if the problem is the router or the adapter.
Don't bother, seems to me that the problem was a cordless phone station placed nearby router. I've set the channel to 11 and everything started working.