I have two wireless networks in my business. One I set up myself, and the other set up by paid professionals (who also checked my set up). Both networks work fine on a half dozen different laptops and notebooks...most of the time. Sometimes, all the computers disconnect, but the signal strengths still show "five bars".

We're using a LinkSys router on one network and a Netgear access point on the other. The business is in a large mall where many other businesses use wireless networks. Sometimes when we can't connect to our own network, we can connect to a neighbors unsecured network. The DSL service is provided by Sprint. The mall is old and known to have telephone line issues, which we can't get the mall to address, but I don't think that's related here.

We've added external router antennas and repeaters, but since the signal strength is always high, this hasn't made a difference. We've replaced the LinkSys router with an identical one which hasn't helped.

Since the equipment seems to be good, and the set ups seem to be good, my guess is that there's some kind of intermittent interference, although it doesn't explain why we can connect to our neighbor's unsecured network when we can't connect either of ours.

Since I'm not formally trained, and I can't afford to pay a pro to sit around all day waiting for the connections to go out, I'm at a loss. Any thoughts or ideas on what we might be doing wrong?

Thanks!!