we have a legacy function that we translated to .net and it came out to more than 5000 lines and the call stack is very deep. In this process when this large method is being called(during the jit process), we get can a stackoverflow exception in .NET 2.0 64 bit, but the same code works fine in 32 bit. I went ahead and added this <disableStackOverflowProbing enabled="true"/> to the runtime element in the configuration file. This made the application runt in 64 bit smoothly