The defense is definitely frustrating at the moment -- and not in the way you WANT defenses to be frustrating (i.e. to other teams!).
But look at it this way: this defense is composed of most of the same players that
8 games ago gave up the NCAA record for rushing yards in a game. This is that same group of guys, only minus a 2nd round draft pick and adding some true freshman. Defense was bad to end the season last year and they're bad (albeit in a different way) to begin the season this year.
I know I'm not the first person to make this argument, but it just goes to show that, while scheme is probably part of the reason pass d is terrible so far, at least part of the problem also has to be personnel (either physically or mentally). Which means it's going to take longer to fix than any of us are happy with.
However, I'm not saying that Banker, et al shouldn't be doing everything they can to tweak the scheme to put our defense in the best position for success. I'm just saying that the defensive problems were so severe last season, and then to come into this season with such a depleted LB core -- it's just going to require time to get everything where we want it.
So try and refrain from being "in-patient"