If it was wired incorrectly at the outlet I would check the wiring all the way back to the main distribution panel and use a circuit tester just to make sure. This is a safety issue that should not be made light of in any way.
As for the performance of equipment, if you can not tell the difference in the performance and the plug is polarized then I would look for another issue in the system such as damage. The basic question becomes, when the power wiring is correct, where is the weak link.
As for the performance of equipment, if you can not tell the difference in the performance and the plug is polarized then I would look for another issue in the system such as damage. The basic question becomes, when the power wiring is correct, where is the weak link.