What do you mean by developers kit? I own the textures and created them myself, hence why I bought the mesh head full perm so I can texture it and re-sell it. I'm just confused as to how I can apply my textures onto the mesh head if you are saying I can't edit it in-world normally. I am now on Firestorm, same issue.
The head is full perm, however when I try to edit it and load my own textures, the texture tab is locked. Same thing when I rez on the ground and edit. When I pick the mesh back up, it shows up as no modify, no copy in my inventory. I did try using Singularity and the standard SL Viewer. I am on Mac OSX. Any ideas how to overcome this? Screenshot: http://i63.tinypic.com/2epkac6.png