Boat Issues-Missing Belt
The hip section of the avatar is the part that moves the least when an avatar changes shape. It has two attachment slots that attach to it: the pelvis, and the stomach. They have different names, but they're both essentially attaching to the hip item, because they move exactly the same way when the avatar movies.
Our decision to use the pelvis slot was somewhat arbitrary. Part of the reason was probably due to the fact we were unaware that the stomach slot was essentially the same slot, though I imagine less used. At least this way we can educate people as to the similarity of the two slots.
Generally, there is one way to solve the problem of conflicting attachment spots, and that is to move your attachment to the stomach slot, realigning it so it fits in the right place.
add in a tutorial about how to detach it and re-align it.
With the Tetra 35, there is another option. You can attach the Tetra 35 detail object to your stomach instead of your pelvis and align it for that slot. This will not work with the SWC and SWC3, as the detail attachment communicates on a random channel every time it's rezzed. The attachment was not designed to be reused, unlike the Tetra attachment, and will not function properly if reused.