if you rename a sketch to the same name as an already existing .java-tab in that sketch the
contents of the main tab will be replaced with the contents of the .java-tab.

- create a new sketch, write something in it
- create a new tab, name it "something.java", write something into it
- rename main tab (sketch) to "something" (without ".java")

this leaves something.pde and something.java in the sketch-folder, both having the same
contents (from something.java)

a little correction: actually the contents in the files are not the same, but the main-tab is
showing the contents of the .java tab, so if you press save you will overwrite your original code
from the main-tab. jumping between the two tabs will bring back the original code in the main
tab.

ouch, okee dokee.. will fix for 0125.

fixed for release 0154, which isn't 0125, but um, yeah.