Also, George Karl was quoted recently as saying "we're schizophrenic defensively". An announcer said he said this a couple weeks ago when they played at Dallas (was on ESPN). Now, obviously that doesn't mean the creation of turnovers, because that's always been a constant for Denver. It's relating to the more typical and legitimate form of playing defense.
i think Karl was just referring to their consistency and effort of playing defense, which wavers dramatically...and typically drops off to nothing when the team collectively thinks they can win a game off talent alone. (see: giving up 46 1st quarter points to indiana, of all teams....and then holding them to 32 in the entire second half)
fortunately that's not a big issue come playoff time. everyone knows they have to play defense to beat the spurs/suns/jazz/hornets...or any team in the western playoffs for that matter. and effort/determination/focus will not waver in those games for that reason.
did denver have an awful defensive period against san antonio last year? i don't recall one. i do recall multiple quarters where they couldn't even get 20 points.
edit: stats to back that up:
denver gave up two 30+ point quarters in the series. and one was the last quarter of game 5 where they essentially threw in the towel.
they only gave up three quarters of over 26 points to san antonio. in 5 games against a team with duncan/parker/ginobili/finley/barry, i think that's pretty darn good....and realistically, it should be enough to win more than 1 game.
on the other hand...denver had 6 quarters in the series where they failed to crack 20 points, one where they scored 11 points, one with 15 points, and one with 16 (in 12 minutes! with iverson and melo!). the only game in which they scored 20+ in all 4 quarters...they won. in games that are consistently decided by 5 points or less, you can't afford to have a quarter where you score 1 point for every minute....or even a 6 minute stretch where you score 5 points.
that's what happens with denver, that's what happened last year.
that's the real issue.