First, thanks in advance for looking at my questions.

Recently, I experienced the problem of non-connecting issue of my wireless router. I used to be able to detect 8-10 networks but sudden I cannot see any but one (using windows). And the one is not mine.

Google brought me here and found the excellent inSSIDer. The following is the results:

The first one shows the results when I use channel 6 (WRT600N is mine). I noticed my SSID jumps in and out of the windows wireless manager. It only shows when there is a high pulse in the inSSID.

The second one shows the reulsts when I use channel 11. In this case, my SSID can be found but no connection can be established. Windows gave the message "connection failed". I noticed that the signal is not a flat line. That's not normal right?

One more finding is that, just outside my window in the open(prob 30 feet away from my router). I can almost detect all the networks. Could a wall block so many signals?

Does this mean something gives my router interference? Is there such strong interference that can even mask the SSID (even though my laptop is right on the top of the router antenna)? I also curious why the another AP (mreh) always shown on my network even though the RSSI is -80 (while my router cannot be detected if the RSSI goes to -80)? Sorry if my question looks stupid to you.

Thanks in advance again for your help.