Blockbuster knows the days of the movie rental store are numbered, as video downloads over the Internet slowly start to replace DVDs. But knowing which way the wind is blowing doesn’t mean you can sail it. Blockbuster’s first box for playing Internet video on the TV doesn’t measure up to competing devices. The company launched the MediaPoint player in November, selling it for $99 from its Web site. The first 25 movie rentals are free. It’s a slim box made by 2Wire that connects to your TV and your home broadband line.