Texture Atlas help

FSMCDesigns

I am hoping someone can help with this. I have used texture atlas a few times on non DAZ, personal models and it worked fine, but i have a few that it does not work properly on. they are UVMapped and have several groups/material zones, but for the life of me i can't get it to recognize the UVmapping it seems as the preview just has one group with the UV layouts over the texture and the rest show no mapping. Any ideas on how to get it to work. Is there a trick to this that i am missing?