Hey there!
Long time listener, first time caller (Bob & Tom reference).
I made this recently: http://www.nexusmods.com/skyrim/mods/56463
Basically, all I did was form the lower parts of a UNP BBP mesh around a SeveNBase Bombshell body. It didn't take long, and it came out extremely well. A couple of days later, a helpful Nexus user pointed out that the offset of the body was off -vs- the hands, etc. I looked at it using the mod he was referencing, and sure enough - it's off.
Anyway, I had a fix done within a couple of hours, except that I used a TBBP body this time. TBBP bodies (in the past) have given me fits for some odd reason, and this one is no exception. The body shows up in-game and looks fantastic at either the 0 or 100 weight settings. When I move the weight slider in RaceMenu to *any* intermediate weight, the vertices twist and distort themselves really badly - almost looks like a transporter accident (think Star Trek I). When I move the slider all the way to the 0 or 100 side, the vertices "snap" back to position as if nothing was wrong.
I use Blender 2.49a, NifTools, etc, etc. I've converted gobs of armor meshes (non-bouncy) with no issues. The only oddities I run into are when I try to do something with TBBP bodies. I've made the modification within nif_common.py to change the max bones per partition from 18 to 60. Before that modification, the result was an exploded mess.
To summarize: non-bouncy bodies work fine, BBP bodies work fine, TBBP bodies melt at intermediate weights.
I am at work, so I can't post some melty nifs. I will be happy to do it when I get home if needed. If anybody happens to know off the top of their head what is wrong (or what could be wrong), I am open for ideas.
Thanks for any help anybody can give me!