Under Eclipse Europa (3.3) with the Floggy 1.1.1 plugin and EclipseME/MTJ if you "Add Floggy Nature" to a project, it causes Eclipse to continually rebuild the project without stopping. In order to make this behavior stop, you have to turn off "Build Automatically."
A patch that solves the continous build
Committed revision 493. Should be backported to branch 1.2.x.