Wireless turns off too fast

I fairly often go out to cafes to get some studying done. Some of them have good AP's but a couple seem to have ones that will reset randomly or lockup.
What I am having a problem with is that my notebook (lenovo 3000 c200) powers off the wireless if it doesnt get connected fast enough.how it usually goes is that I have gone into my connections and told it to stop trying to connect to the security enabled network from down the street and to get on the unsecured network in the cafe. That network crashes, comes back up, then my wireless is off! It's that fast, about 2 minutes give or take a bit.
I've gone through the configuration settings for the interface and disabled all of the power saving and hibernation for it.

 

Update the drivers and see if that helps.

 

I'm already at the most current for all my drivers

 

It might be a problem with the router itself; in which case you can't you anything about it. You can try to ask the owner to update the firmware

 

hmm thats a good suggestion. Unfortunately I have this problem with more than one router/location. Also I am positive its my wifi. When I dont hurry up and get online, the green antenna light stops blinking. Then when I refresh my available network list I get no networks and a message that the "radio" is not active.
On the bad router topic. I did notice that whenever there are a lot of macs around at my regular cafe the router starts acting up. Do Macs spew packets or something?

 

Look into replacing the wireless NIC/Adapter. I don't know about what effects Mac's have on Wi-Fi.

 

A) I am not annoyed by it enough to get a new wireless card (broadcom 802.11g,seems to work fine most of the time)

B) I really need to get a packet sniffer and check that out next time I am there.
It's funny becuase its a mostly mac cafe, and I think they think I cause the router crashes. But when I go there early in the ams before the slackers roll out of bed there wont be a problem for hours.

 

Interesting let me know the outcome.

 

One thing to check. Download a copy of Netstumbler if you are running XP. If you not running XP, I d not now what other free scanners are out there. Run a scan when you first get there, get a baseline. Continue switching back n forth between your connection. You may find out that 1 user is causing all the problem. May be a ill behaved 11n device that the user has not kept up with updates. Or a user running Adhoc trying to break-in or setting up a rudge AP/client to intercept ID & passwords.