Assuming all the time was originally entered using the same billing rate, the different Billing Rates showing on the invoice are a product of the invoice style combined with write ups and write downs. If an invoice style is NOT designed for Discount Logic, the Timekeeper Recap will show a line for each Timekeeper for each effective rate at which the time was billed.  To avoid this, tell Orion to keep the rate constant when you perform a write up or write down.

The Bill Preparation – Write Up/Down function performs a true calculation of time multiplied by rate to get the bill amount. Therefore, if the rate is not held constant, it will be adjusted so the above formula is correct.  If the rate is held constant for this Matter, Orion will adjust the time (unless there is a rounding issue).  The formula of Bill Time x Bill Rate = Bill Amount must be mathematically correct so there may be some instances when the Bill Rate cannot be held constant.