Altium bug or me doing something wrong?

[dmg]

I have to send a design to a PCB manufacturer that for some reason can't tent vias with soldermask and it does even require a fairly large soldermask aperture for vias, meaning that the smaller vias (0,55mm pad diameter) turn out almost fully exposed.  set up the "minimum soldermask silver" rule to the manufacturer recomended with the following restrictions:

-First object isVia
-Second object isVia or isPad

That way it won't report 264283423426423 errors because of no sufficient soldermask between pads on fine pitched QFN's and such, because those are handled by the manufacturer.

So I route the board, it passes DRC and inspection, visually looks good and during the inspection phase I corrected some minimum soldermask silver errors because I placed vias too close to pads, something expected. I also checked that my design rule was working properly. I send the board to the manufacturer and it's put on hold because there are 5 places where minimum soldermask isn't met. They've sent me a picture of the violations and sure enough, vias are a little bit too close to pads and violating the rule, but altium isn't finding these errors. There's nothing special I can see about these places, they should have been detected and reported but they weren't, while all the other similar errors were. I'm trying to recreate the situation and experiment but it always detects the error.

Has anyone expected something similar? It's altium 14 but i'm being upgraded soon.