ECC stands for Error-correcting Code. RAM with ECC has an additional chip in the center of the memroy stick. All outgoing and ingoing information passes through this chip, where the RAM makes sure that the information hasn't been corrupted. In theory, it works great, since it prevents some corruption problems. But, it makes the RAM slower overall, and a lot of motherboards won't accept it. ECC memory is most commonly used in servers (usually registered ECC memory, at that).
Unfortunately, no, there really isn't a way to work around this. You'll have to return them and buy non-ECC memory.