I will check to see if I have a firewall installed in my Ubuntu installation on
the eeePC. I did not install one, but it may be lurking in the background
without my knowledge.

As for your problem, I have found that lower resolution means one of two things,
either you are using the wrong video driver or you monitor is setup as a generic
low res one. I am using an Nvidia card (6600) and when I first install a distro
I need to install the restricted driver for that card to get all of its
features. Occasionally I find a similar problem when I install a new distro that
does not support my card (rare these days, but more common a year ago). When I
checked the settings they were vga and all I could get was 800 x 600 with only
basic vga colors. When I installed the right driver I got proper resolution and
millions of colors. I sometimes found that Compiz would not work until I set the
monitor to my proper monitor type (LCD) with the right size (17 inch) and
refresh rate. I used the repositories to find the right graphics card driver
(restricted) and changed the monitor settings manually to the closest match.