Hello,
I'll agree with the others, and say that if the memory shows bad in any test that I would be concerned.
But, as for which one I would take most seriously, I would trust Apple's in this case. There are two reasons:
First, Apple's hardware test rarely has a false positive. It will miss problems with memory more than it catches them. So, if it finds a problem, I would consider it a definitely problem.
Second, this is the only test that Apple is going to take seriously and care about. They are not going to rely on your findings from an unsupported 3rd-party program. Since they cannot control the quality of that other test, they are not going to replace parts based on it's results. So, they will only take the results from their own tests seriously. And, you can call them with the error code that the test returned, and they will issue a replacement part for you (assuming that it is their memory module that's bad and not one you installed from somewhere else).
I hope this helps.
Let us know if you have other questions.
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