An outdated document and a customer complaint indicate that Comcast employees are (mistakenly) telling some customers of its Extreme 105 service that they cannot use their own modems and must instead rent equipment from Comcast. “So I purchased the Zoom 5341J to take advantage of the 8 downstream channels now available here,” a Comcast customer, apparently from Virginia who goes by the user name “ExoticFish,” wrote on a DSLReports forum Monday. The customer continued: “Since then I had some issues, not speed related necessarily. So normal customer service was unable to resolve them so I E-mailed Comcast’s “Executive Support’ team.” I got a call today from a guy. He was the rudest Comcast rep I had ever spoken to, EVER! Not only did he not resolve anything but he told me my modem is not approved for my package.”