I recently switched from DSL to cable. No issues on DSL. Since switching to cable, I haven't been able to connect more than one computer to the wireless access point at one time. I have three computers, one running W7, one on xp, and one on Vista. All three of the computers have been able to connect to the WAP when connecting alone.
I am using a wap54g linksys access point. Setup is internet --> coax --> cable modem --> ethernet --> wap