Luck elixir not stack.. or not work?!

[Boltmage]

So I was chatting to a guildie who told me he was using luck elixir from the auction and he opened one as the other was running out and it didn't work.. so I decided to test as I thought that couldnt be right.
I waited in a map until 10 seconds left on the first one and opened another and as he said when the 10 second timer ran down I had no luck elixirs active! Now I completely understand them not stackin ie 25%+25% doesnt =50% and that time doesnt stack ie 30 mins + 30 mins doesnt = 60 mins...but opening a new one when one almost finishes then losing 29min 50sec of luck seems a little unfair? Also I had no idea about this and am now wondering how long iv been running around with no elixir thinking 'damn this elixir sucks better off using plat bought'
Is this a bug or another way to milk gold from non plat users?