Wheel wobble under braking!?

Cambered road probably causing it...Nothing you can do really. Best way is to test by braking hard on different roads.
 
^^ Exactly this. Take it to a flat freeway and brake hard. If it happens again then something is wrong but if not then it was just uneven road.
 
I had the same problem - vibrating only on light braking, not when hard on brakes

dealer disgnosed it as warped discs. They skimmed the front disks and I had to pay for it - problem went away ...........for 1 week, now it's back

I won't skim my discs every week, will live with the problem till I get the KTR grooved discs