TiVo, the company that makes the technology behind the digital video recorders sold by Philips, Sony and others, is facing a lawsuit over its pause button. Boston, Massachusetts-based Pause Technology filed the lawsuit in the US District Court in Boston on 28 September. The lawsuit alleges that TiVo infringes the US Reissue Patent 36,801, which describes the use of a "circular buffer" to constantly record one or more incoming audio or video signals so that the user can pause a programme at any point, and then either continue viewing from that point or jump forwards to catch up with the real-time broadcast. The patent, titled "Time Delayed Digital Video System using Concurrent Recordings and Playback", was filed in October 1992, issued in December 1995 and then reissued in April 1996 and again in August 2000. According to reports, TiVo was notified on 4 April, 2000 and again on 23 May, 2001 that it was infringing on the patent. Pause Technology offered to extend the offer to discuss licensing terms, but the process was unsuccessful. Andrew Cresci, vice president of TiVo UK, said he believes the lawsuit to be groundless. "We are surprised and disappointed that Pause Technologies has launched a lawsuit on TiVo. The patent that TiVo was awarded earlier this year does not infringe any of Pause Technology's patents." TiVo recorders first appeared in UK shops in October 2000, and are sold on a lifetime subscription basis for a one-off fee of £299. The devices store up to 40 hours of programmes on hard disk rather than video tape, allowing viewers to pause, rewind and play back live television in slow motion. Have your say instantly, and see what others have said. Click on the TalkBack button and go to the ZDNet news forum. Let the editors know what you think in the Mailroom. And read other letters.