Generally the fittings are softened by the welding process, did you lubricate the fittings before you tightened them? I use anti-seize on all AN fitting threads for this reason.
I usually have no issues with Torques UK fittings, the latest batch of 4an teflon braided fittings had a 30% leak rate, but a few extra olives had them working again. Good quality for the price, and he is more than happy to help with issues, unlike Proflow...
If you want guaranteed quality and operation go with the Speedflow gear, I just can't justify the price.