CRM-12869 This is a temporary fix from Eileen which prevents the over-write. However...

CRM-12869 This is a temporary fix from Eileen which prevents the over-write. However it also prevents the billing address from being saved for the payee, and requires the user to know that they need to manually replace the billing field values with the payer data. In general I do not think this record payment from a differnet contact feature  is production-ready (even though it is part of 4.3). Selecting a different payer should reload the the billing address fields with the payer info.

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* CRM-12869: Record Payment from different contact causes email and address to be altered in contacts record
  http://issues.civicrm.org/jira/browse/CRM-12869