AOL seems to have issues of its own. What type of connection do you have? What modem/router brands & model no.'s do you have? Where are you trying to connect from (home, school, work, etc.)? How much ram do you have? Which OSX version do you use?

For your video files, QT may have difficulty playing some. So might I recommend VLC: http://www.videolan.org/vlc/ (choose the nearest mirror site.) VLC will play everything except the odd wmv file. You would need to make VLC the default to open certain types files you downld. eg: I have vlc as default to play wmv, asf & if I have difficulty with any other I manually open it with vlc. To make a default, select a file & hold down apple & i keys & look at Open with & choose your app. Then choose always open with.