Re: Black Screen on Ubuntu 10.04
Are you able to log into the laptop remotely from another computer? If so, you should be able to generate an nvidia-bug-report.log file so that we can have a better idea of what is happening.
Based on your problem description, though, I suspect that you are experiencing a problem which is caused by an unimplemented ACPI method in the driver which is required for display detection to succeed on many laptops, particularly recent Sony VAIO systems. The next driver release (current release is 256.35) should have this implementation in place, so if you can wait until then, please try the next released driver to see if it resolves your problem.