Help!!I recently installed Hardy Heron, from a live CD i burned (and checked) myself.I managed to successfully set up my wireless (using ndiswrapper), and install a driver for my Nvidia graphics card.After installing / removing some applications, using the standard 'add / remove software' app, I got told the system needed a reboot.So i rebooted - my laptop turned off, turned on, the bios came up, detected no boot cd, then the ubuntu splash screen came up, with a progress bar (as usual). However, when the progress bar got to the end, the screen simply went blank, and after a second the ubuntu login sound was played.This is as close as i get to logging in - the screen simply stays blank, and my mouse/keyboard dont have any effect. When i push the power button to turn my laptop off, i get a quick flash of a bios screen, and then the standard ubuntu splash screen with a progress bar showing shutdown progress appears.What can i do? What is causing this? Am i being a complete n00b and missing something? Please help!