Spent sometime last night reading the DayZ forums for a solution and noted the following from a few members:-
1. On some servers, after pitching camp, leave the tent empty and allow at least one full cycle of server-shutdown-reboot before the tent will work properly; and
2. Tent duplication appears to occur if the tent had been repacked and unpacked. What this suggest is you avoid duplication if you pitch a new tent once and never repack it again to move it to another location.
I don't know how reliable are these suggestions, so I'm going to test them out and report back here. Cannot play for the next couple of days though due to simracing commitments with my LAN group. Meantime I'm using UH-1 in Arma2 singleplayer armoury to tour Chernaurus to scope out some potential camping spots. It's the one sure way to familiarize myself with Chernaurus in relatively safety. I'm pretty handy now with nap-of-earth on the Huey. If you ever need a pilot and don't mind some low as snakeshit reckless flying, feel free to drop me a line