Z445 cut issues

I have a 2+ year old Z445 with a 54" HC deck with only 104 hours on it because the year I bought it turned out to be the drought of record in Texas and I only mowed three times. This year the starter and solenoid had to be replaced (1st trip to the dealer for service). I took the deck off before taking it in so I could clean out the underside, sharpen and balance the (Predator mulching) blades and clean and lubricate everything while the Kawasaki was being worked on. Once I got it back (3 weeks, I almost needed a baler) and reattached the deck, I mowed my 3 acre yard twice to get things back under control. Anyway, since then I have noticed that the cut doesn't seem to be even, with the area traversed by the middle of the deck being taller than the outside on each side. Most of my "yard" is crappy old Bahia grass, except for some San Augustine right around the house. I dont' know if the striped effect is because the tires are pressing down the grass on the outsides and it isn't springing back right away or if I did something wrong when I put everything back together. Does anyone else have this type of problem?