This is not true. If you combine the following about:config settings with your ssh -D command, it works:

network.proxy.socks localhost
network.proxy.socks_port 3210
network.proxy.socks_remote_dns true
network.proxy.type 1

And remember, http://whatsyourip.org/ is your friend.

Why Nokia left the SOCKS fields out of the advanced network settings is a mystery to me, but there's a bug filed. Please vote for it; it's easy to find if you search for "proxy."

And as far as entering numbers in about:config: You can only get the dialog by selecting the field. and pressing the physical return key. Then, when the dialog comes up, close the keyboard and use the virtual keyboard. Bizarre, but it works.