Four third lenses aperture blades on E-P2

Hi, I'm Edwin, a new member in this forum, I just bought my own E-P2, I also owned E-620 DSLR.
My new E-P2 came with 14-42mm kit lens, and I also bought the MMF-1 adapter, so I can use this new baby with my older four third lenses
Then I notice, that when using my older four third lenses (all of them: 25mm pancake, 50mm macro, 12-60mm SWD and 50-200mm SWD), I see that the aperture blades of these lenses always react when I point my E-P2 to brighter light. The aperture seems to be closing in -excuse my English- (getting smaller).
Is this a normal thing with the PEN series? Especially E-P2?
I would be grateful for all your replies.
Thanx before

 

Thanx Brian, that's what I thought so, something to do with the live view, to protec the sensor maybe, but I have to make sure 'bout this, since when I try the live view system on my E-620, this thing never happen to me.
Thanx alot man.