I have a rather old Linksys WUSB11 Wireless-B USB adapter that worked fine with my old D-Link DSL-2640T Wireless G router. However when I changed to D-Link DIR-615 router, problem arises. My USB adapter keeps disconnecting for a few minutes and reconnects to the router. Signal strength was averagely 3 bars that time. It was used on Windows 7 Home Premium 32bit. Any idea on why is this happening? Thanks in advance.