As HP Mobile Hotspot didn't work for me, I decided to give freetether a try. And it worked... Once.
The testing procedure:
Initial state: freshly booted up system. 2G network. Advanced right corner menu patch installed (later on called device menu). Data is off. I'm in Poland, the operator is Play.
1. In the device menu enable 3G
2. Enable data connection
3. Take a random google - mobile internet works
4. Close the browser
5. Start freetether
6. Start wifi tethering
7. Connect a device: here: Nokia N900: works
8. Google something on N900: works
9. Disconnect N900
10. Disable tethering
11. Turn off data
12. Enable 2G only
13. Close freetether
14. Repeat steps 1-6
15. The freetether network is not being detected by N900, a computer (Linux Mint 15) can't connect either
What am I doing wrong?
I'm not sure if this is important, but the DHCP server dot is lit up even after disabling the tethering...
/edit: after another reboot, the DHCP dot (and the other one) aren't lit. When I enable tethering they light up. When I disable it back, they don't die.