NSAutoreleasePool with Json Data
I gather that request2 is an instance variable?  It's risky at best to set it with an autoreleased value and then expect it to be valid later in your displayView method.  

But it probably works because you execute receive in a background task, and background tasks have no default autorelease pool.  If it weren't for that request2 would likely go "poof" before it got to displayView.

So all of the autoreleased data items in receive -- post2, dataToSend2, request2, several temporary strings, and at least one temporary URL -- are leaking.