It's a tight fit, but you can use both together.
I actually prefer it as using the bare phone in the case by itself can lead to problems if you are going to wear it on your belt/hip.
Check out my vids in this thread:
http://www.everythingicafe.com/forum...ved-23185.html
Again, I am not saying that the Vajacase is bad, just that there is a slight design problem which I doubt can be addressed without making significant changes to the design. I think I am the only person to have noticed this problem so far. It was a freak accident that I hooked my phone (in the vaja case) on a door handle/push plate and had it pop out and hit the pavement.