Both pairs had one good chip and one bad chip and each pair was sequentially numbered, they gave be the Corasair for the same price as I made 3 trips to the store to upgrade the ram.Which latency was it? 10 or 11? I installed the CL10 1.5V RAM in my wife's and had no problems. (Plus it was $44.99 at the time with discounts at Newegg).
My wife's had problems with Mushkin. I was able to RMA it back to Newegg with no out of pocket costs. Had no problems using G. Skill for my late 2008 MB or early 2009 iMac getting them to 8GB total.
You probably would have been better off with Crucial RAM.