I know this is an ancient forum thread, but:
DO NOT MIRROR HOLE WIZARDS!!!
Try your absolute best to use a circular pattern instead or some other pattern to get the quantity to work on your drawing.
I've got a pattern of a pattern and it's working. I'm not sure if you can do a 3rd or more.
(Kevin's linked post is about mirrored parts, not so much features I think)
To work around this problem you can 1) mirror the sketch points of the hole wizard feature position sketch, instead of using a Mirror feature, or 2) modify the dimension text of the hole callout and enter the desired instance number.
Like Scott stated, a circular pattern will work (this actually my preferred work around). But I can tell it will not always be this way...