Connecting to Ichat; Display Issue

[neptune]

Hi,
These are my first questions on your site.

I am using my son's old G4 Powerbook (867 MHz; 1 GB ram) connected to the new 20 inch cinema display. I use Tiger. We are wireless here using the airport express base. I have been using a Mac for 17 years, but I am not technically gifted.

Questions:
1. All of a sudden yesterday, I was unable to connect to iChat after using it without problems for 6 weeks or so. My son just told me he is also not able to connect today. (He has a new 12 inch powerbook.)

2. After returning from a movie tonight having used my computer all day without issues, I could not wake it up. I turned it off and restarted it. The display did not "fit" the size of the monitor (it was smaller than the monitor size), so I went to system preferences and selected 1280x800, which stretches the image across the monitor, but which has everything looking larger than previously (with a large font size and icons larger, etc.)

Thanks in advance for any help you can provide.