Please feel free to use the search function on Greek Chat; there are wonderful, informative threads that contain a plethora of useful information about preparing for recruitment. You can spend a few hours reading today while the turkey is in the oven!
Follow up with the Greek Life Office regarding your GPA. As has been pointed out to you in other thread(s) you've started, your GPA is a starting point for looking at why you were released from all six chapters this past fall. The 3.0 GPA you report - is that based on your attendance at every college you've attended? When considering transfer credits and grades, typically the credits will transfer and the grades will not be used in calculating current GPA. So, your GPA from the three semesters (or is it just two?) that you've been at UND is what will be considered/reported; the spring semester 2011 at another college won't count.
Personally, I don't see the benefit of asking current actives (whom you describe as acquaintances and not close friends) why you were released. Membership selection is private and the answers that you get are not likely to be helpful to you. In other words, they won't tell you. They can't (unless, of course, it's something obvious that you haven't told us; for example, you were convicted of a felony.

).
It's really pointless to search for reasons; that's in the past. You have time to do the research and learn how to improve your chances. This is assuming that UND is offering some sort of spring recruitment; otherwise you'll be going through in Fall 2012 as a senior (age wise) and that, honestly, is not a promising prospect (even if you are going to be in school extra years).