I bought new boots last year after skiing the same skis for two seasons, and suddenly, I just did not have the control over the skis like I was used to. Two things were going on: 1) boots were too stiff, and 2) I needed toe lifts.
But I am also in agreement that you could just have a tune issue going on since you recently had the skis tuned.
Who knew skiing could involve so much detective work?!