MacBook Pro WiFi keeps shutting down for no apparent reason I've got quite a problem with my Macbook Pro (late 2010, running OS X Lion 10.7.3).
Since a few days ago, my wifi frequently keeps shutting down. It starts by the network not being functional and then when I switch AirPort off/on, it does not want to switch on. It keeps being switched off. Only a restart fixes the problem. But it keeps coming back.

I already reset the SMC and P-RAM, nothing helps.

Is anybody familiar with this problem and might be able to help me out? I would appreciate it.

Best regards!

Here's what I could discover in Console that might have something to do with it:

3/7/12 6:15:24.000 PM kernel: AirPort: Link Down on en1. Reason 8 (Disassociated because station leaving).
3/7/12 6:15:25.657 PM UserEventAgent: CaptiveNetworkSupport:CaptivePublishState:1211 en1 - PreProbe
3/7/12 6:15:25.664 PM configd: network configuration changed.
3/7/12 6:15:25.667 PM applepushserviced: &lt;APSCourier: 0x7fb0e9d0c3f0&gt;: Stream error occurred for &lt;APSTCPStream: 0x102d294c0&gt;: The operation couldn’t be completed. Socket is not connected
3/7/12 6:15:25.682 PM applepushserviced: &lt;APSCourier: 0x7fb0e9d0c3f0&gt;: Stream error occurred for &lt;APSTCPStream: 0x102d294c0&gt;: The operation couldn’t be completed. (kCFErrorDomainCFNetwork error 2.)
3/7/12 6:15:25.685 PM applepushserviced: &lt;APSCourier: 0x7fb0e9d0c3f0&gt;: Stream error occurred for &lt;APSTCPStream: 0x102d294c0&gt;: The operation couldn’t be completed. (kCFErrorDomainCFNetwork error 2.)
3/7/12 6:15:28.192 PM applepushserviced: &lt;APSCourier: 0x7fb0e9d0c3f0&gt;: Stream error occurred for &lt;APSTCPStream: 0x7fb0e9e17270&gt;: The operation couldn’t be completed. (kCFErrorDomainCFNetwork error 2.)
3/7/12 6:15:31.000 PM kernel: VendorID check timed out ! Issuing secondary bus reset 
3/7/12 6:15:32.000 PM kernel: WLAN adapter not yet powered or is not in the system (stateNumber = 1)!
3/7/12 6:15:32.000 PM kernel: wl: syncPowerState called when card is down.
3/7/12 6:15:32.000 PM kernel: WLAN adapter not yet powered or is not in the system (stateNumber = 2)!
3/7/12 6:15:32.000 PM kernel: wl: enable called when card is down.
I've had the exact same problem before with my Mid-2010 MacBook Pro. I took it into the Apple support people on campus and, after running quite a few tests, they found out that the cable connecting the AirPort card to the motherboard had gone bad. It sounds like this is the same thing that you're experiencing, so your best bet is to see about getting that cable replaced.