HELP! I'm in the middle of converting my Eclipse app from 1.4 to 5. Previously, I had been able to go to Java Compiler, and swap the "compiler compliance level" from 1.4 to 5, and BACK, and it worked fine. Now, it SAYS it's doing a build, but it's not producing any classes when I swap back to 1.4. (And it's taking one second, instead of the usual five seconds.)
In the Package Explorer window, my project DOES show a red "x", but none of the source files is similarly marked. I have checked that my libraries are all there, and they are. I have deleted all the classes, and tried to rebuild, but no luck. And I have tried making trivial changes to code, in case the compiler felt nothing had changed, but no luck there, either.