Okay. So, I've had the issue of my wireless connection working, then randomly going to limited connectivity, requiring a restart to fix. Was bugging me to all hell.
Then, I noticed that if I just have my PC on, and never run anything, it stays on. Then, I left my PC on with just uTorrent running, and it stayed on. But, once I turned on Firefox, my connection lasted minutes.
I thought that was strange. So I changed to just using IE8, and my connection has been on for more than 12 hours.
So my solution is: Try not using Firefox. I haven't tested to see if it was addons that are creating this problem, but firefox definitely creates the problem for me.