Ok. I recently installed ubuntu on my macbook pro. Unfortunately, while trying to install the nvidia graphics drivers the system wouldn't reboot, the screen grey for hours. I concluded that I had broken ubuntu, and proceeded to boot into osx and remove the ubuntu partitions. After I had done that, after a reboot, I noticed that "boot linux from hd" was still listed in the bootloader (i'm using rEFIT). I dismissed it. Now, I'm trying to reinstall ubuntu, using the same USB that I successfully installed with earlier. Now, however, when the ubuntu installer is on the "copying files" part this error (more or less) pops up. ERRNO 5: We're sorry, the installer crashed. This error frequently is caused by faulty installation media, the hard disk being too hot... and so on and so forth. I'm not sure what's causing the problem, but I have a hunch that whatever's the reason that's causing linux to show up in rEFIT is the root reason. If anyone could respond, that would be great.

PS, and unfortunately no, i do not have a time machine backup.