iOS6 multiple account app update issue?

I have 2 iTunes account, probably a lot less than many people here, one from when I was living in NZ and another I made after moving to Australia. The Australian one is my main account now and is where most of my currently used apps have been purchased, there are still a few on the NZ account.

Recently I updated DoDonPachi Blissful Death, purchased on the NZ account. After iOS6 you no longer have to enter passwords when updating from the AppStore, which is neat, however it doesn't seem give any prompts when updating an app from an account other than the one you are logged in to. Rather than simply update from the NZ account, the game was repurchased using my Australian account with no notifications or confirmations at all.

Has this been happening to anyone else or was it just a freak occurrence? I can't remember which account a lot of my apps were purchased on and if the only way around this is to completely sign out of my account on the device and in to another then this is going to end up being a huge (and potentially expensive) hassle.

 

Almost 100% certain, but didn't want to try test it any further which is why I made the thread to see if it had happened to anyone else. DDP Blissful Death was last updated on the AppStore on the 14th, I "repurchased" it on the 15th which would have been when I updated it. All done within the updates tab on my iPad (did not visit the store page for the app).

 

Yeah, I mentioned that being the "fix", but I have so many apps I'm not 100% sure which ones are from what account anymore. Most are from my Au account but there is still a decent amount on the NZ one. Also completely logging out and in to a new account is a bit time consuming especially when all you used to have to do was enter the password for the appropriate account.

I am hoping this was an AppStore/iTunes error and not how it would normally happen, so wanting more input from others.