I have burned the iso image of Precise Pangolin to disk but I am worried about installing it because when I first installed Natty Narwhal I had graphic problems With the unity 3D desktop which were solved by downloading and installing Unity 2D as advised to do on this forum. I have tried running the live c.d. and it seems to run without any problems on my system so can I assume that installing Precise Pangolin will not cause any problems.