a box is checked that says disconnect if idle after 20 minutes
or you need one of those nifty little programs that make you appear to busy at your computer. plus if you get disconnected
during any download then you need a download manager program that re-establishes your connection and re starts the download where you left off.
third reason is: yeah prolly juno sucks... try this one slingah ...
http://www.gis.net/ ->galaxy rules in my opinion as i used them for my DIALUP connection and will so again if i return to dial up... right now i have DSL over my cable with 768 donload speed... wicked fast,,, but when i had them ok i would often crash with my computer left on and i'd still be online in the morning many many times. Plus my personal record of staying online non stop was 47 hours straight without being disconnected. so that proves how good it was. See if their service is available in your area.