Why am I seen as a group spammer?

Hello,

Let me first say that I absolutely love this add-on, it has completely changed how I form groups in WoW.  With that said, I have used the add-on many times to create groups, and because people rotate so quickly in and out of Flex SoO runs, I am constantly picking up more people from OQ to fill the raid up.  Just the other day I cleared flex 3 & 4 with a raid I assembled from trade & OQ, and after we called it on Garrosh because people had to go, a couple of people told me that they received a whisper stating to ban me for group spamming?  What exactly did I do wrong?  I also have people showing up on my ban list for "auto-add: group spammer", can someone tell me why this is happening?