Are the all-seasons tied to the rolling direction? If yes, do you know if they were mounted according to the rolling direction? They were rebalanced while they were off the vehicle I think (right?), maybe there was some rust or something else at one hub so one wheel was wobbling a little bit. The rust could have been cleaned when the tires were changed.
One other thing: if you plan to change the tires regularly, it's much better having two sets of rims where the tires stay on over the season. Mounting and dismounting tires on rims regularly can lead to failures which aren't visible normally. Additionally, if you do regularly change tires it's much better having dedicated summer- and winter-tires, all-seasons are neither here nor there.
Why E10? I'm driving E46
"Captain Slow is doing is doing 360 kilometers ... 370!
It's no wonder Michael Schumacher retired - he's slower than me!" - Captain Slow @ TG 09x02
"A10 Ascari? A10 Tankbuster more likely!" - JC - Supercar Showdown