This error cropped up on my x64 Linux Mint installation. It turned out that the result was a failure in the ADB binary, because the ia32-libs package was not installed. Simply running apt-get install ia32-libs and relaunching Eclipse fixed the error.
If your x64 distro does not have ia32-libs, you'll have to go Multiarch.
Check #4 and #5 on this post: http://crunchbang.org/forums/viewtopic.php?pid=277883#p277883
Hope this helps someone.