I've updated the hack so now it works in K2i as well. Details can be found here: Unicode Hack for International Kindle
I've tested it on my device and it installs and uninstalls just fine. I've also tested this new version of the hack on K2US and Kindle DX - no problems either. If you have V0.1 of the hack there is no reason to update. Functionally they are identical. Most of the changes are in the way files are installed and uninstalled.
Some people have asked for 100% clean uninstall so I've implemented it.
I've also tested screensaver hack to K2i from the other thread and it works fine with UFH.