Bought a wheelset from an online retailer.

Within 50 miles, I was getting a creak from the rear wheel. Took it to my LBS, and the mechanic says "spoke tension is all over the place." He detensioned and retensioned the spokes, no more creak.

100 miles later, I am getting a creak from the front wheel. It's at the LBS right now for the same service.

Is this to be expected, comes with the territory, etc., or might it indicate that the wheels were maybe not so well-constructed?

Thanks in advance...