I've not had any problems carrying the 120ml size either (and come to think of it neither has the fella). In the states I always make mention that contact lens solution falls under the heading of "medical supplies" and thus is not necessarily subject to the 100ml (or 3 oz or whatever it is) rule.

Funny thing that, after *years* of this limit, it's still nigh on impossible to get 100ml bottles of contact lens solution. I did find one bottle at a big mega-lo-mart on a trip to the US last year. The bottle was specifically marketed as "carry-on through airport security!" or something, but that's the only time I've seen it on either side of the pond.