release vs debug in msvs .net 2003

Hi,
I am puzzled. I have a function that computes some value but the problem is the value returned is different if I compile in debug mode than if I compile in release mode in microsoft visual studio .net 2003. I am really puzzled as to why. Any help would be highly appreciated. Thanks
Amish

Your code has bugs in it.
First guess would be some uninitialised value being used before you've assigned an initial value.