I think it's a quirk in Poser 4 itself. Try the following: Load Posette and the women's T-shirt. Conform the shirt to Posette. Disable IK on her legs, or otherwise things will get even uglier in a moment. Okay, ready? Select Posette's hip, and set the Side-Side dial to exactly 180 degrees so she's upside down. Watch what happens to the shirt. Try it with Bend and Twist, also. Now try it with different clothing items. For some reason, the bikini top, biker shorts, and miniskirt work okay. I no longer have a clue why, although I still suspect that IK, or the lack thereof, might be a factor.