When I try to get on the internet through a wifi connection, it says the tablet may not be connected. I've tried this on several wifi connections.

You clicked on the connection and a message came up saying "the tablet may not be connected"?

It should ask you for the access key if you click on a wifi connection.

Of course, that's only true if the AP is not open.

If the user is clicking on an "open" (shows as an open padlock) AP and getting this message, it's entirely possible he (or she) is connecting to an ad-hoc network, and not an actual access point... thus, "the tablet may not be connected" to the internet, just to whatever ad-hoc network he/she found.

The way to tell is to look at the wifi icon in the status bar -- if there's a dot above the wavy lines, you're connected to an ad-hoc network.

I've never actually seen a dot the way you describe. You learn something new every day.

Is there any way to tell from the list of connections whether it's an ad-hoc connection?

However, it seems unlikely that ALL of the connections that the original poster detected would be ad hoc, surely some of them must be internet connections?

No way of knowing without input from what they're seeing there. If they're sitting in their car in a residential neighborhood (not their own), the only "open" connections they see may be ad-hoc connections, with the rest being WEP or WPA secured, internet-enabled wifi connections.

Certainly, at their own house, they should be able to see their own wifi AP and be able to connect normally, but without getting a more complete story from the original poster, it's hard to diagnose.

Yeah, that's true. More and more people are aware now about securing their connections (which is a good thing).

As you say though, this shouldn't cause them problems on their own connection or on a genuine public hotspot.

Is this wifi referred to a known working wifi ap? ie: your own network etc and tested with a laptop. Some open/public wifi networks like panera bread require you to accept terms first.

Still do not get and have never seen the tablet may not be connected error.

Is it possible this might be the default web page which appears on some pay-for wifi hotspots if you're not a member?