Hello Peter,
It looks like you are checking values of the TcxCurrencyEdit or TcxCalcEdit in-place editor. Hence, I've created a sample application with QuantumGrid with two cells and assigned these two editors to them. The aqObject.CompareProperty method works correctly with the sample. I've attached the sample project.
Can you reproduce the problem with the sample application? If the comparison fails, please pack the entire project suite folder with the test that fails and send it to us. If it works correctly, can you modify the sample Delphi project or create your own sample to reproduce the problem?