John, are these outlets controlled by the three way swithes? Are just half of the duplex outlets switch controlled? As Joe D said, there are many ways to wire 3 way switches depending upon where the power comes in. What do these swithes control?
Your first mistake is assuming the outlets are wired correctly. 3 way switches require 4 wires, 2 hot conductors(one of which is the traveler between the switches), a neutral, and a ground. Among many things, you could have an outlet wired with a traveler or when half of a duplex receptacle is switched, then both halves need to be wired separately with the tab in the middle on the hot side removed. There are so many possibilities it is hard to troubleshoot over the web. Never assume anything.