Hey Yuri,
Me and a couple of engineers have looked at your VI and found that there are a couple of possible causes of this border change. I found out that if you set a border on the destination of the cast image, it is overwritten by the border of the source image when it is cast. So the destination buffer takes the border size of the source at runtime. I by passed your temp image subvi with an IMAQ create and the border size stopped changing. If you write the desired border to the source file instead of the dest file, then it stays the same through the Cast.
I hope this helps you out. It took me a while to track down a possible cause, but I am pretty sure it is something inside your subvi. If you are still experiencing this problem, could you possibly strip down your VI to the smallest possible amount of code where you are still seeing the problem, and I will take another look at it. Since I was unsure of what everything's purpose was in your image creator subvi, I did not want to try to bypass code and inadvertently remove something important that may be causing the problem. Let me know what I can do further for you Yuri!
Take Care,
Evan D.
Installer R&D
National Instruments
