Authorize.net error 11 Duplicate Transaction

Authorize.net is responding to subscription payment with "A duplicate transaction has been submitted." It is subsequently voiding the transaction in Authorize.net. The subscription is made up of 13 access levels that are 1 month in duration each. Members will progress from one user level to the next automatically. It is set to charge the same amount every month/access level until the 13th month, where the final access level is free.

I do not have this problem when purchasing a subscription that only has 1 finite access level. My guess is that it is firing an ARB and and AIM request or multiple AIM requests at once... either on purpose or by accident I don't know.

I am using the latest beta, because the latest stable release has a bug which I could not work around.

Please help me get this working. I've been paying for this plugin for months and my support has been sub-standard or simply non-responsive and I am yet to be able to use the plugin. I really want this solution to work for me.