Take a look at the original ring that came on that crank. How do the teeth line up laterally compared to the crank's mounting tabs? When replacing the stock rings on some cranks with rings from other brands, I've ended up with rings that were too close together or too far apart, which can cause shifting problems. I try to solve this by adding spacers between the tabs and the ring or dremmeling away some of the material on the ring where it mounts.

TA rings are great for giving you more gearing options, but unfortunately they'll never impress you with their shifting quality, longevity, or stiffness. As well as having many TA rings, I have one pair of rings by Stronglight (33/48, 110 BCD) with their special CT2 finish, which they say should improve durability. I've been very happy with those in terms of shifting and durability so far, so you could give those a try if you don't have any luck with the TAs.