Shawn, We've been trying to track this down for a couple days now and I've come up with a very strange but reproducable solution. (at least on my installation). I've been trying over and over again and it seems like whatever value is listed in the seventh line of Offer Codes in the Realm Override field is showing up as the new user's realm. I tried putting values in the Realm Override field in the lines before line 7 and the lines after line 7 and it doesn't seem to have the same problem. I tried changing the Offer Code ID in line 7 and it didn't make a difference. I made the offer code blank and it didn't make a difference. Whatever value is in line 7 realm override is what gets used. If there is no value there then it defaults to the system default override. I will be real anxious to hear if this only works on my installation or if you can reproduce it there.
Yeah, finally figured that one out. It has to do with you assigning a specific account class to the first company. It's not necessary because anyone that doesn't match a specific account class will always be part of the first company. It's okay to assign the account class to the customer record if you want, but it's not necessary to assign the first company an account class under the More preferences.