The nvidia bug report you include shows the results with Intel graphics - not nvidia so it's hard to put a finger on the problem. You shouldn't need to reinstall an OS because of graphics problems - just boot to single user mode and remove the automatic starting of xdm/gdm/kdm - whatever your sesssion manager (ie gui logon) is, and reboot again (or "telinit 3" may work). From the console "startx" starts the gui.
Having distribution (eg Ubuntu) packages of nvidia and running the nvidia installer manually can cause conflicts and breakage - there should be only one driver in other words. Remove the previous driver before installing the next.
For new users it is probably better to stick to distribution packages and not perform a manual install.
In any case please remove this from xorg.conf,