What are the minimal system requirements for game? Has the new version become more demanding, or not?
I've tried running the game on an old notebook with Precise 32bit, Nvidia 7400, 304.43 proprietary driver, and it looks like a slideshow, with xorg pegged at 100%. Compiz doesn't work well on that hardware, so I use Unity2d. Version 0.7.3 worked well in Ubuntu 10.04 on the same machine.
PS: For my own reference, the way to install the backported version is:
sudo apt-get install supertuxkart-data=0.8-1~ubuntu12.04.1 supertuxkart=0.8-1~ubuntu12.04.1