Closing the GUI does help sometimes. However, avast! will kick up again when I start to intensely use the internet. It seems, whenever I start something (youtube clip, file download, etc) avast! has to finish downloading and scanning before moving on (of course, I don't get the file)
As for testing, I performed two more tests recently, and both showed even less free bandwidth. I also tried the cnet (speed test) version as well. It only downloaded at 56kb.
When I uninstalled avast!, everything worked fine (uninstalling of course removing the whole program, so, not chance of retirement services or processes). I got full speed, but, the idea of having no AV was rather disconcerting. However, if there is a difference in effect between uninstalling and disabling the service, I'd still be interested to try it out.
However, as of now, most of the time it's fine. It still is an issue however it it kicks up--as I have no idea when it will stop. For example, right now I'm downloading at full speed. However, I'm not sure when/if avast! will begin to act up.
P.S. In reference to telling avast! if I have a permanent connection (as opposed to dial-up), checking that I connect via dial-up seems to help some more as well. I just tried selecting them both, and I'll report back sometime as to the results.