Only 2 things I can think of:
1) When filing a Mortgage Modification with the County Clerk; the additional monies may not have the same lien position if another lien has been filed since the original date.
2) If the current mortgagors are different now (due to death, divorce, marriage or transfer of ownership), it could really mess up your standing in the event of foreclosure or bankruptcy.
I suppose an updated title search may take care of these. This would be a good question for an attorney.