Snow Leopard threw me off the web: WiFi and T-Mobile 3G USB Stick connectivity woes
I just upgraded to Snow Leopard and immediately found myself severed from the Internet: I couldn't connect to the BTOpenZone WiFi network (or see any other networks) and neither could I connect with my T-Mobile USB stick.
Removing the Automatic location in System Preferences → Network → fixed the T-Mobile USB stick issue (you have to add a DIAG connection and set the telephone number to *99# since the web 'n' walk app that comes on the USB stick – which I wasn't using anyway – crashes under Snow Leopard).
After making this change and turning Airport off and on again, I was able to connect to the BTOpenZone network but the connection dropped out after a while and it returned to not being able to see the network. I restarted Airport again and initially it gave me the new Alert: No Internet Connection message (see screenshot) and then finally connected. Fingers crossed, it seems to be staying up this time. Although the BTOpenZone networks at Starbucks appear to be entirely unreliable themselves (frequently crashing and having to be restarted those times when the actual Internet connection itself isn't a roller coaster ride of dropouts and slowdowns), my iPhone had no trouble whatsoever seeing or connecting to the same network.
So, although the new usability enhancements in the Airport UI look good (e.g., telling you when you're connected to a network but don't have an Internet connection), it does appear that the actual connectivity is much less stable. Ah, as I was writing that it lost the WiFi connection again.
My T-Mobile USB stick connection, on the other hand, appears to be solid (and the dial up process is faster now) since I trashed the Automatic location.
I'm assuming I won't be the only one encountering WiFi issues with Snow Leopard so here's hoping there will be more workarounds and quite possibly a patch posted soon.
I would have loved my first post on Snow Leopard to have been on the user experience improvements, etc., but those don't really matter when the most fundamental feature (the Internet connectivity) takes a step back in terms of stability.