Ubuntu 11.10 nits

Since upgrading my Dell Latitude D610 to Ubuntu 11.10, two nits:

1. My computer seems to drop the wireless connection, and the only way to restart it is to reboot. Without warning, the system is suddenly offline, and fiddling with the Network widgets doesn't bring it back online. ifconfig down/up doesn't bring it back online, either. But rebooting it gets me back online with 100% reliability
2. The screen dims when the computer is idle for a certain period of time. Then, after waking it back up from screen-dim, the screen lights up, but then slowly darkens again to an almost-dim state. If I then go into the Displays control panel and fiddle with the screen resolution (e.g., set it to a different resolution but then revert to the current resolution), the screen becomes bright again.

I'm not sure what's causing either of these problems, and I'm not sure how to diagnose them further. For the time being, Ubuntu 11.10 on this computer is a bit of an annoyance.

Oh, by the way, 3 other computers that I've got which are running 11.10 are not displaying these symptoms. Just this one.