If you are using Fixed Allocation Accounts in GP with AIT, you will not be able to post to those Fixed Allocation Accounts at this time. The cross-company verification process that AIT uses indicates that the Dexterity procedures that would verify Allocation Accounts no longer function properly in GP 2010 because this is now handled exclusively by stored procedures.
If you attempt to post to a Fixed Allocation Account, you will get the following error:
Value of range.
If you currently use Fixed Allocation Accounts, you will need to convert them to AIT Templates to maintain that functionality until we revise the Dexterity procedures in order to maintain the thorough AIT cross-company verification.