In some weird cases doing:
0) Install new current version of NSP GK5 (re-install)
1) Open module in edit mode
2) Click Refresh button in your browser
3) Change data source to another from list
4) Change order of showing items
5) Save changes - check on front page
6) If okey, change data source back to option which you have at the beginning
helps, but if not - it is pure nsp configuration issue.