Comcast is disputing assertions voiced by several Ann Arbor residents that today’s cable TV network upgrades would cause TiVo digital video recorders to lose some functionality.

But TiVo offers a different perspective. The company's site indicates that digital network upgrades prevent dual-tuner TiVo users from simultaneously recording shows on two digital channels.

Comcast, contacted by AnnArbor.com today after several residents expressed concern, said the digital upgrades wouldn’t affect TiVo units. That directly contradicts reports by several residents, who said their TiVo units would not work correctly with newly required Comcast digital equipment.

“TiVo DVRs are fully compatible with Comcast digital equipment and will allow you to access all of your channels,” wrote Mary Beth Halprin, vice president of public relations and community affairs, in an e-mail.

But TiVo's Web site indicates that dual-tuner users will encounter problems.

"Your TiVo DVR can record one digital channel and one analog channel or two analog channels at the same time. That does not change," TiVo's site says. "However, since your cable provider is broadcasting more of your channels in digital format, you may see more recording conflicts after you install your cable box, and some of your scheduled Season Pass recordings may be affected."

Several Ann Arbor residents confirmed that their dual-tuner TiVo units do not work correctly when connected to Comcast digital equipment. Comcast today is upgrading a portion of its analog cable transmission to digital technology. The upgrade means that cable users whose TVs don’t have digital capability need to install free Comcast equipment to ensure uninterrupted service on all channels.

Halprin said in an interview that she was previously “not aware” of incompatibility between the Comcast equipment and TiVo technology.

“I can’t speak to a specific customer’s issue. And there are a couple of different versions of TiVo out there. So there could be some issues with the way that it’s installed,” Halprin said. “But without knowing what’s happening at the customer’s television it’s difficult to give you a specific answer.”

Jane Raymond, an Ann Arbor resident and Comcast customer, said she spent time discussing the issue with TiVo and Comcast representatives. Her dual-tuner TiVo, she said, can no longer record two shows at once.

“There’s no way you can do it,” she said. “They must be getting hundreds of these phone calls, but yet they acted very surprised. They were not very helpful.”

TiVo public relations officials were not immediately available for comment.

Raymond suggested that the upgrade was a ploy by Comcast to entice cable customers to buy a Comcast DVR.

Asked for her response, Halprin said: “The project is connected to providing new services through our video service, our on-demand programming and our Internet service. The equipment that a customer chooses to have depends on their lifestyle.”

Halprin said Comcast was responding to customer concerns on a case-by-case basis. She provided this advice in an e-mail:

“TiVo Series3 DVRs (including TiVo HD and HD XL) will work without a digital cable box because they use CableCARDs to receive digital channels. Digital adapters are not needed. TiVo Series2 and Series1 DVRs require a Comcast digital cable box or a digital adapter to receive digital channels. If customers have questions about setting up their TiVo DVR with a digital cable box, they should check their TiVo owner’s manual. Depending on the TiVo equipment, there are multiple ways to connect TiVo to the Comcast service. For more information, customers can visit www.tivo.com/alldigital.”

Contact AnnArbor.com's Nathan Bomey at nathanbomey@annarbor.com or (734) 623-2587. You can also follow him on Twitter.