TiVo might have quite a battle on its hands, as Microsoft has sued TiVo over an alleged patent infringement in its DVRs. TiVo is accused of copying Microsoft’s Mediaroom IPTV technology in the DVRs themselves, the software and the subscription based service. If this goes Microsoft’s way, it would effectively block TiVo from selling DVRs without a licensing deal. This suit is similar to AT&T’s lawsuit against TiVo, claiming that the media boxes violate patents from AT&T’s VDSL-based U-Verse service. The good news (for TiVo) is that Microsoft has begun talks with the company to reach a deal without going through the courts, so maybe they’ll be able to work something out amongst themselves.