I also have the same problem, sometimes it takes just 1-2 resets to be able to boot, and now i reseted the computer 8 times (2 with full power off) and it finally booted. I think that it fails right before showing the Ubuntu logo and progress bar when switching from console to graphics mode.
My computer is HP Pavilion dm4t-1100 wit ATI 5470HD and Intel.
I also have the same problem, sometimes it takes just 1-2 resets to be able to boot, and now i reseted the computer 8 times (2 with full power off) and it finally booted. I think that it fails right before showing the Ubuntu logo and progress bar when switching from console to graphics mode.
My computer is HP Pavilion dm4t-1100 wit ATI 5470HD and Intel.