WinXPSP2 Slipstreamed CD

Hello to all. I have a small question, that I hope the smart people in this forum can answer. I have made slipstreamed CD's with WINXPSP2 included. I did this with both the Gold Code and with SP1. The iso files are different sizes for each CD! I have done this twice to make sure that it wasn't an error on my part, and results were the same each time, and both CD's install with no problems. The slipstreamed CD with the Gold Code is 488 megs. , and the CD with SP1 is 511 megs. I'm puzzled as to the size difference, as I've read that SP2 contains all the SP1 fixes. All answers welcomed and appreciated.

 

Please disregard my original post! I failed to check if SP2 was installed with the CD burn using the Gold Code. It wasn't. My error, and thanks to all that have read.