Why do you think this is abnormal? Why should both programs stress your CPU as much as each other? How do you even define running a processor at 100%? Doing what form of task?
I'm sure if you run another stressing program (Intel BurnTest or something) you will get a different temperature again, depending on how your CPU handles that certain type of task.
I wouldn't be worried, those temps are fine, and being only 4 degrees apart is pretty darn close in the scheme of things =)