Wifi issue: connecting but no access

[Convectuoso]

Hi everyone,
I know there are a lot of threads about the Fire's Wifi issues, but so far I haven't found something like mine:
My Fire displays Wifi networks just fine, it connects to them (shows 'connected' next to the network's name), but the WiFi icon on top still displays the 'x' next to it, and no internet features will work.
I've tried connecting to several networks, but the result is always the same.
Does anyone know how to fix this?

I'm running system version 6.3.1

[fdalbor]

Do you have any of the wifi analyzer programs on your fire so you can measure the signals you are trying to connect to? I have found that if you have a signal that is below 85dBm's it will usually show as being connected; but will not allow you to get enough data to have a working connection, hence the x next to the connection icon.
I know my fire (which is also a 6.3.1 original) has no problem once the signal is above 85dBm's and when I can get above 80 its great. Once it has made a working connection (no x next to the icon), the signal can get as high as 90dBms' and it will still maintain the connection.
Have you gone to a public wifi spot with a high reading and still not be able to get a WORKING connection, or is this just at some wifi points? I know in several instances I have made a connection at say a Barnes and Nobel and then have several people come in later and also make a connection and then the signal gets weak enough that the x appears and I can no longer use the internet.
However if you cannot get a working connection even with a strong signal then the problem is deeper. fdalbor