Caravaggio, I might be reaching here. Consider the length of your animation and the dynamics your requiring from that cloth. I don't have the details of you simulation but going off what you posted about how you set it up...well... I dunno. Choosing a pose at frame 15 and another at frame 30 is fine, the problem resides in the fact that, well... That is only half a second of animation. Sure the dynamics are a big help in how it will interact in the animation but I think it is one thing to go from pose A to pose B in 2-3 seconds rather than expecting 15 frames to truly give you what you need. Also, you don't need to be set to zero at frame 1 for your sim to work/drape properly. The draping process put your figure at zero pose (if checked) when it starts calculating the drape. If you need more drape time, up it. Also up your stepping, its like drape frames for drape frames i think. I'm not saying you need to change this, just give that some though is all. :) glad things are working out for now.