One problem with 3G / Wifi Kindle is that they do not automatically switch from wifi to 3g when the configured wifi is not available.
This was a problem as I was in an area with no wifi at all, and would be a problem if there was only protected wifi.
To get round this you need to override the default setting of 'automatic' for selecting which wifi connection to use and manually select the correct 3G one.
This can take several time consuming iterations. But instructions are here.
Luckily I found what to do on my blackberry as that was the only internet connection i had available.
One problem with 3G / Wifi Kindle is that they do not automatically switch from wifi to 3g when the configured wifi is not available.
This was a problem as I was in an area with no wifi at all, and would be a problem if there was only protected wifi.
To get round this you need to override the default setting of 'automatic' for selecting which wifi connection to use and manually select the correct 3G one.
This can take several time consuming iterations. But instructions are here.
Luckily I found what to do on my blackberry as that was the only internet connection i had available.