I have the exact situation going on right now with my Aero car. I had all 4 sway bar links replaced and a 4 wheel alignment done right before I went to Hallett last weekend.
The car drove fine Sat, but somewhere between Sat and Sunday it developed the same characteristics - twitchy and unstable (the exact words I used to describe how it was acting). The front end felt like it was floating above 75mph, and I had the same tuck/grab get me sideways in a corner where I've never had a problem before. (I was chasing a GT3 pretty hard through the corner at the time, but I'm sure that had nothing to do with it.
)
The car tracks straight down the road, but the steering wheel is sitting at the 1:00 o'clock position.
I too didn't get a read-out.
Did you take your car to your normal place, or did you use the guys I go to - just for comparison? (Don't want to name names, because both places are normally flawless in their work)
I'm bringing my car back in next week to get looked over and I'll be back at Hallett on the 30th, so hopefully it'll get figured out.
Let us know what you find out.