Wireshark crashing

Hi all, thanks for being here. I'm running Wireshark 1.6.7 on Ubuntu 12.04.Total newbie.Left side of screen "capture" box says "no interface can be used for capturing in this system with the current configuration". Striking 1st top left icon for "listing available capture interfaces" gives me a pop-up box with a red circle w/ white bar inside stating "There are no interfaces on which a capture can be done." striking 2nd icon from top left "show capture options" gives me a "capture" config type box. After entering the 1st letter of my interface name wireshark crashes,shuts down, gone. What the hey ? Right ? I have set the described permissions for non super users to capture packets.Now have a new "red circle box", sez "Couldn't run /usr/bin/dumpcap in child process: Permission denied". after removing those permissions again, i now am seeing the original "no interface can be used for capturing in this system with the current configuration". Hand up to the new guy ? thanks