If you are getting the message "Problem with Audio Playback" while trying to make call with skype 2.0 on Linux, then you need to do the needful.

Go to - Options (By pressing Ctrl+O or by clicking Skype symbol on the bottom left and then clicking Options)

Then go to Sound devices and change Sound In and Sound options to pulse instead of Default device. Say apply and then close.

Things should be fine !