I'm unsure of your work path here, you exported from Poser via goz. when you Goz'd back into poser didn;t it ask if you to name a new morph for the mods? If so you should have had no reason to copy in a new skeleton. If you saved a new obj and brought that into Poser, there is your problem ZBrush only exports GROUPS not Mat zones so if you used the Material zones options when sending to GoZ in poser your Materials will be converted to GROUPs not mat zones. I usually use UVMapper pro to fix this but you may need to run the obj back thru your modeller to remap the mat zones

Easier to GoZ it back in as a morph (FBM) and save the obj from Poser and re-install, or just set the morph at Min 1 Max 1 which will 'lock" the morph as active.