X isn't working with nvidia geforce, no screens found

X isn't working with nvidia geforce, no screens found

I recently installed ubuntu on a Lenovo Y500 with a Nvidia geforce chip.
startx does not work.
First I was told that module nvidia did not exist, so I installed
nvidia-current, which eliminated that issue. My X log file says my driver
ought to be supporting my gpu. However, the file also returns the
following warnings:
Falling back to old probe method for vesa
Falling back to old probe method for modesetting
Falling back to old probe method for fbdev
And eventually:
Failed to initialize the NVIDIA GPU at PCI:1:0:0.
Failing initialization o x screen 0
So for some reason my GPU isn't initializing, even though my driver should
be working with it.
Running startx reveals:
NVIDIA: could not open the device file /dev/nvidia0 (Input/Output error).
But that doesn't get recorded in the log file, for some reason. In dev, I
can find the nvidia0 file, but when I nano it it's empty. I suspect this
is because of the file type, not its contents and I'm just being stupid,
but I thought it might be relevant. Nothing else I can think of reveals
anything about this file.
So I thought, maybe it's a permissions issue. Sudo startx returned the
same results. Logging in as root changes nothing.
I am now stuck. I can come up with nothing else. Help me, askubuntu,
you're my only hope!