timing problem when programming with smart snippets

Hi,
I use TIMER0 in my profile which triggers SWTIM_IRQn interrupt every 5ms. The profile works fine when I program it in Keil or with connection manager, however when I use smart snippets, the timing of timer becomes so slow (the timer interrupt triggers every 30). It seems that the clock frequency is changed by programming with smart snippets. Also, some header bytes will be added when loading the hex file of keil project's program into smart snippets application. I am wondering what these bytes are and where they are loaded from!
Does anybody have any idea?
任何帮助都是appreciated. Thanks.