After purchasing the TurboTax Live upgrade and speaking with a CPA, we (along with the help of his manager) determined that entering the AMT adjustment amount in the 'Other Tax Situations' interview DOES in fact DOUBLE COUNT your taxable amount if you have already entered it in the 'ISO Exercise and Hold' section previously. They would not go so far as to call this a bug, but they're looking into adding clarifying language or an alternate path if you've already this taxable amount. They were able to view all my Tax forms and confirmed that entering the AMT adjustment amount in both places - even when prompted - will double count the correct amount.
So I'm no tax expert and take this with a grain of salt as it may not be appropriate for your situation, but upon the CPAs suggestion, I am deleting all info entered into the AMT interview related to ISOs and only entering this information in the 'ISO Exercise and Hold' section of wages. Good luck!
