Display Member List in Popup

Hey folks,

This question may sound very "noobish" but I have no experience with coding so far. Anyway I was trying to get Gallery to display the users/members of my Gallery in a popup. The problem i encountered is that I cant get the module to display the users. I do get the standard table with the heading username/reg date etc. but it is not populated with any data. What are the commands to display users in a simple popup?

I tried copying the memberslist.tpl but still dont get any data...

Any help at all would be much appreciated.