bootloader burning

I am using arduinos for prototyping and development … On all designs I am working with, I noticed that strangely the bootloader requires to be burned after every compile with my MKII and AVR studio. # 0774023179 # 077 40 23 179 # Now I also noticed that therre are here several threads describing similar scenarios but everytime these are on several different arduinos. I was wondering if someone has an answer to this ?

Thanks in advance.