ITIN is an Individual Taxpayer Identification Number that you can apply for and use in place of a SSN on your tax return. ITINs are for federal tax reporting only. Did you use a ITIN when you filed your 2010 return? Do you now have a SSN?
If you used a ITIN when you filed your 2010 tax return and now have a SSN then when the program asks for your 2010 AGI you need to enter zero. (also leave the 2010 PIN blank, do not even enter a zero), then the program should ask you to create a PIN for 2011.