WE recently purchased “HBO on Demand.” You know what happens when you switch to HBO on Demand? A graphic appears. It reads, “Please Wait.” But perhaps we’re too demanding.

The Nuggets-Timberwolves playoff game Wednesday tipped off at 10 p.m. Game 4 of the series this Tuesday begins at 10:30 p.m.

Last month, we were appalled by Canuck Todd Bertuzzi’s garbage-time attack on Colorado’s Steve Moore, a retaliatory assault that left Moore’s neck broken and his career in doubt.

This week we’re appalled that the Knicks didn’t retaliate in Game 2 for Jason Collins’ Game 1 garbage-time flagrant foul against Tim Thomas.

Yesterday, during the Marlins-Phillies on ESPN, Phils’ exec Ed Wade, talking about his club’s new stadium, admitted that placing the visiting bullpen within spitting distance of the fans had created some “security issues.” In Philly? Who’d a thunk it?

Are you starting to get the picture, or are we still in the “Please Wait” phase?

Yesterday morning, during “SportsCenter,” ESPN promoted its coverage of tomorrow’s NFL Draft by reminding us that ya never know. After all, Stephen Davis, the promo told us, was the 102nd pick in the 1996 draft.

Ya never know is an excellent point. In fact, you can watch all 17 hours of ESPN’s NFL Draft coverage and you’re still not gonna know.

Speaking of the draft and ESPN, the latest edition of ESPN’s magazine poses several of the anticipated top draft picks in full, bad-dude scowls. Yep, ESPN attitude dictates that we prefer our athletes to look as if they’re about to slit our throats.

Frankly, I have a hard time rooting for fellows who appear to want to do me harm. I’m sure some of them are a lot nicer than ESPN chooses for them to appear. But ya never know.

ESPN Radio-NY’s Don LaGreca, like most everyone else on ESPN, lately can be heard riffing about steroids, ephedra, andro and other dangerous and occasionally deadly substances that have laid sports low.

Tuesday, LaGreca read an advertisement placed by the sponsor of the update he was anchoring. It was an ad for “an amazing, super pill” that promotes “rapid weight loss” – a red light claim and often a dubious one, according to sports medicine experts.

If, what LaGreca was handed to read is true, then the product is dangerous. Or hadn’t ESPN yet heard? Hey, dude, either that’s an Arena League halftime score or your blood pressure’s tanking!

Yesterday, in the top of the seventh against the Mets, the Expos batted, in order, Ron Calloway (.050), Termell Sledge (.030) and Brain Schneider (.150). Seven non-pitchers on the Expos are batting under .200. Only two are hitting over .250. The Expos, 1-8 vs. the rest of the NL, are 3-4 vs. the Mets.

Mike Piazza yesterday didn’t run out a fly ball. Again. He presumed he was out. Again. And he was wrong. Again. So, when the fly ball was misplayed, he had to risk an injury by sliding into second. Had he run moderately hard from the start, there would’ve been a lot less risk.

Not running out fly balls to cut down on the risk of leg injuries has long been used as an excuse for Piazza and other stars who treat fly balls with fashionable indifference. Yesterday, it could’ve had the opposite result. Again.

Speaking of overly indulged stars, the Sixers this week hired another new coach for Allen Iverson. Gosh, I hope it all works out.