I'm running up Jaunty, my laptop is one of the VAIO series with the Video card using the 180.44 closed driver.
I found that I can't adjust my brightness with the GNOME applet, it tells me "cannot get laptop brightness" and moving the slider does nothing.
If I use smartdimmer package in the Terminal, It just works, it does too if I launch NVIDIA settings panel and set it from there.
I did some searching and googling oo Ubuntu forums and Lauchpad bugs but despite similar issues had been found, they were related to older kernels than mine (2.6.28-15-generic)

I'm seriously thinking about filling a bug report, but seeing that it might be related to the close driver, maybe it's just widely known issue, and it's enough to wait for the next driver release from NVidia, or should I report this right away?