Question about generating C code from simulink blocks

When using Matlab 2011, simulink block PID(z)'s generated code does not work when moved to a target device. However when the equivalent structure of PID; that is gain block for Kp, discrete integral block for Ki and discrete derivative block for Kd is used for the same constants. The generated code works. Is this related to the version of Matlab being used? If not what is the possible reason?

[Ryan G]

What is the process for generating code and putting it on the target? For a simple discrete PID control you should be able to read through the generated code to determine what it is doing.