Im going to scream..ibook d/l dropping plz help before i kill

im just so sick of it! i cant download or stream anything, gets approx 3rd of the way thu then stops, it works fine hardwired but i share the web with housemates wirelessy so i cant do that as well, its wireless for all or hardired for me, router is a belkin 54g. if anyone can help i would be amazingly grateful
some details
OSX 10.4.11
intel ibook 2.16
please have a heart and help a poor downtrodden fool
peace