I have found with version 160 that if I remain too long looking at "Recent Prints" that Hipstamatic freezes up and requires I re boot the iPhone. Anyone else experiencing this?

yes, same thing happens to me. I think there is a bug with OS4...

I experience this problem frequently. Sometimes, the viewfinder does not open also.

Rather than rebooting, I double tap the home button, press and hold the Hipstamatic icon and then close it via the red circle.

Similar problems here. I frequently need to restart the app. iPhone 3GS, iOS4.

Yup, same issues. I wrote to the developer... no reply.

On twitter and facebook, a call for beta testers for the next update seems to indicate that they are doing more rigorous testing to ensure that the next update is bug free.