call to calculate tax: Applying prepayments

I have a theoretical question for you guys:

On certain prepayments (not all)  we cannot apply prepayments due to an error identified in note 1197123.1.  The error message is set out below:

APP-SQLAP-10000: An unexpected error has occurred in Apply_Prepay_line<- Apply prepayment form with parameters (&PARAMETERS) will perfoming the following operations:  Call to Calculate tax.

We have not changed anything other than updated some combinations on certain bank accounts so we cannot work out why this should start happening all of a sudden.

My question to you guys is:  If we create a new tax rule that excludes prepayments from tax will this stop the above problem happening.  I intend to uncheck the "Allow tax applicability" flag for prepayments in Configuration owner tax options.