Make sure the libraries are in your build path. In eclipse right click on your app, say Themes/Ushahidi and select Properties -> Java Build Path -> Projects. Make sure Core is added as a required project on the build path.
The same for Core. Right click on the Core project and select. Properties -> Java Build Path -> Projects. Make sure abs and menudrawer are in your build path. cwacmerge was recently removed as a required library. Edited the wiki to reflect that.
Also, for both Core and your white-labelled app, when you’re at Properties -> Java Build Path -> Order and Export. Make sure Android Private Libraries is enabled. This is a new thing required by the build system.
After,clean your projects. Restart eclipse. It should be good. Otherwise you can find me on IRC as eyedol on irc.freenode.net #ushahidi or the Ushahidi Skype dev chat.