Fair enough. Often ISP techs will recommend use of the WEP level of wireless encryption because it allows a weak signal to seem more robust. 

 However do not use less than WPA2 unless your more than 5 miles from a location from which another may hi-jack your signal. Another thing to restrict by configuration specifics the other devices on the network and how, when and for what duration each may access the web. Otherwise you maybe allowing the wireless network to bleed off bandwidth...and that may be what you're experiencing now.