Originally Posted by countmattula
I think I might have found another way to fix this "force close" error when the phone switches from 3G to WiFi and vice versa, or when you disconnect from a computer via USB.
for the Captivate with 2.3.5 installed:
1. Put your phone's USB setting to Mass Storage:
Settings>Applications>USB settings>Mass storage.
(this way when you connect your phone to your computer via USB cable, it won't be in Kies, or Media Player mode).
2. Connect the phone to your computer via USB, but don't click the button "Connect storage to PC"
3. Hit the "Home" button on your phone and go to:
Settings> Wireless and network > Teathering and portable hotspot >
and you want to un-check "USB tethering"
disconnect, and you will not see the error message when switching from 3G to WiFi and vice versa, nor will you get the error message when plugging in your phone to the USB. NO FACTORY RESET REQUIRED.
As far as free tethering... well that is a separate issue, and I'm sure you can find out about that with a little searching on Google.
When I did this I found that USB tethering was already unchecked. So I unplugged my phone and got the tethering error again. Then I plugged it in again, went to mass storage mode and went back into settings and checked the USB tethering box. It then displayed "tethered". So I went to the browser to see if there was any change with the connection, didn't seem any different, so I unplugged the USB cable and to my surprise there was no error! I plugged it in again, went to USB tethering and saw it was unchecked again. Unplugged the phone and still no error.
It seems all you need to do is enable USB tethering once to fix this problem.