Printf Oddity : Programming Challange

[DarkAlex]

Here is a challange for the FIRST programming community. I promise a super-tremendous prize, like a candy bar, at nationals to whoever figures it out.

The Challange:
Recently, aka for nobody knows how long but recently found, we have had a problem with our autonomous program where we have vital print statements. If we remove certain printf statments, now named vital, our program stops printing anything out and tries to run backwards through the closest wall. We don't really know how long it has been in the code, because we normally left the 'vital' print statements in anyway just because they were useful. However, we were running out of code space and trying to cut down on memory usage and we took one out and discovered this problem.
We did some experimentation and discovered that it didn't matter what the vital print statements printed, but they had to print something. Integer, just "Nothing," it didn't matter. The spots where the vital print statements had to be were seemingly random places in our code, at the very beginning, when we move through our 3D data structure. We managed to eliminate the need for one print statement by correcting a small error in our data structure, but the other one remained. We tried almost everything, moving statements around, adding them at odd places, nothing eliminated the need for the statement.
At first we suspected a syntax error somewhere that the print statement was, somehow, correcting. No luck. Then we thought of stdio. It didn't matter whether we included it or not or where. Again no luck. Ok, at this point we'd pretty much accepted our odd print statement as a permenate part of our code that we're just going to have to deal with. It was something we worked on in our free time. Not that we had that much time, but it bugged us enough to occupy all we had.
Eventually I randomly removed the initialization printf statement in User Initialization in User Routines (that is included in the default code) and suddenly our code worked. No other print statements were required anymore to stop it from trying to kill us.
I don't understand. Does anyone understand? This doesn't make logical sense that the initialization printf statement would require a second statement to stop it from destroying our program. Keep in mind that we have not edited that statement at all since we got the default code. We have had various programmers proofread our code. No one has found any odd syntax error or statement re-declaration.

Summary:
1) Without some vital printf("..."); statements our program does not work
2) With some vital printf("..."); we start at nearly the right place in our data structure, but one step too far
3) When we remove all but the vital printf statements our program works perfectly
4) When we remove ALL the print statements in our seperate autonomous file, and also remove the default initialization statement our program works perfectly.
5) We use 3 Interrupts. I'm not sure this is significant, but I always suspect interrupts.

Here is the question that must be answered: Why?

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