I would like to be able to enter negative amount gifts to use instead of adjusting a gift. This is becuase we use Post-O-Matic and it does not post $0 gifts (adjustments). This would allow us to adjust the gift and still use POM to interface with our accounting department and their software.
PostOmatic should reverse the previous gift amount if it has been adjusted to $0 and the original amount was posted. If it doesn't, it is a bug that should be reported to support@omaticsoftware.com to be fixed. It appears to be working correctly in the test I just did. You can also contact me directly at steves@omaticsoftware.com , I am the developer that wrote POM and I will be happy to try and resolve the problem.