My Sony VAIO's screen went dim a couple of days ago.

I was blaming 8.04 because it happened after up-grading.

I decided to try running my live cd of 7.10 to prove it was 8.04 and, sure enough, after 7.10 loaded, my screen was as bright as ever.

I re-booted into 8.04 and now my screen is back to normal.

Beats me!