Bad batches happen, that's why you should test before adding to your tank. It can help a lot.
I had good luck with Brightwell's for 2 5G buckets worth, than got 2 bad batches in a row and will never go back to them. It happens. The levels were terrible and I was dosing constantly. I knew they were bad because I tested ahead of time, but the buckets weren't cheap so we just used our two part to get through it. I tried Red Sea Coral Pro back in the Fall of 2010 and was very unhappy and even had a phosphate reading.
Out of all the salts I've tried, I've had the best luck with Coralife (I know, surprised me too), AquaVitro Salinity (by far the best I've tried) and Tropic Marin Pro.