Yeah, the rules aren't especially clear. In my groups, we take the "veils are a block against perception" to mean that before any physical action taken against someone under a veil, the attacker has to make some kind of perception roll (usually Alertness or Investigation) and if they can't beat the veil, they can't directly target the person under the veil.
Zone-wide attacks, of course, can still hit, and you can do maneuvers or invoke aspects to get around it, but otherwise, you can't hit what you can't see. Also the veil would drop if you did something obvious, like decking someone or firing off an offensive spell.
My group felt this way fit best with how veils are used in the books, and maintained the rulebooks' statement that veils are special.
Another alternate that I proposed back in a long and, uh, contentious thread about veils was that you could also treat it as a reverse ambush -- if you fail the perception roll, you can still make a targeted attack, but you'll be rolling from 0, since you're firing blind.