My plan - my question. (IAP)

Braydon_SFX

Hey guys,

My plan is, now that I have Pro, is to make Penguin Pounce free with 20 levels. (the first world)
I have an IAP for them that unlocks the other two worlds for $0.99.

Now here is my question:
The people who have already downloaded my game (They did buy it)
When they get the update, will they have to purchase that unlock to get the levels they already paid for?

If that's the case, is there any way around it?

POM

I had this problem when i wanted to update my game The Loonimals Toy Box , i wanted to give 3 games free and the option to unlock the others via IAP , first i thought using the device clock to check who previously purchased the game , then i thought using the scoring system (if the player has a score above 0 that means he already played the game before) , at the end i decided to simply release a new different version of the game with this feature , i suggest you do the same ..
Make a new game - "Penguin Pounce Free" and release it on its own .

Roy.