If it were me, I'd be doing my weights and cardio on separate days.
If you can't swing that, then I'd start sipping your shake 30-40 minutes into your weight routine, so its gone by the time you start cardio. Will keep you in positive nitrogen balance (anabolic) so you shouldn't be hurting your muscle development while doing the cardio.
The way I see it, you need some kind of exercise every day, or at least 5-6 days per week to keep the engine running hot.
Since only professional bodybuilders and athletes have hit the point where they can manage weight training 5 days a week without doing more harm than good.
So for all of us 'amature' enthusiasts, 3-4 days a week of weights is all you can really do effectively, which leaves 3-4 days open for cardio (or just general exercise like shooting hoops, playing flag football, tennis lessons, judo class, etc...etc...)
If you try to pile it all into three workouts a week, you just won't see the same results as someone who spread the same workload out more evenly.
Teh body really works on trends, not day to day activities. If it worked day-to-day, you'd be able to gain or lose a pound of fat in 24 hours just by taking in or restricting 3500 calories...and we all know it ain't that simple