All Accounting Periods erroneously marked as New Fiscal Year

One of my customers has erroneously marked all of their Accounting Periods in 2012 (normal calendar month) as 'New Fiscal Year'. And did also close all these 12 periods with the 'Close Year' function in the Accounting Periods form.
Now, trying to post the 'Close Income Statement' for a fiscal Year Ending Date of 31-12-2012 results in journal lines that will only post the result of the month of December.

I advised my customer to run the 'Close Income Statement' for each Accounting Period that has the 'New Fiscal Year' check-box ticked, i.e. 12 times for each Fiscal Year Ending Date: 31-01-2012, 29-02-2012, 31-03-2012, etc.

Would this procedure cause any inconsistencies in their Trial Balance for 2012 or Fiscal Year Balance?
Any comment is appreciated!
Btw: they use NAV5.0SP1.