ZBrushCentral

split up uvs

Hi guys
I run into a very annoying problem when exporting an obj from Zbrush. I remember it is not the fist time it happens. All my uvs are split up after exporting. I tried merging them in Maya and then re importing the obj in Zbrush but then again when I export the mesh from ZB all uvs are split up. I want to mention that the Mrg button in the export section is ON.
Thanks in advance