Hit Ctrl+F9 in Intellij IDEA when JRebel does not work as expected

Often the solution for a problem is so damn easy when you know the cause of the problem ...
Intellij IDEA doesn't have an autocompile feature similar to Eclipse. So if you want your new code to be generated as a class file you have to hit Ctrl+F9 manually.
Well, the same is true when using JRebel. This great piece of software can only detect a change in a class file if the changed class file is generated by a compiler first.
So in case you are using IDEA in conjunction with JRebel and you wonder, why the heck this new code isn't replaced by JRebel on the fly you must hit Ctrl+F9 to generate a new class version and to trigger JRebel afterwards.

One other thing to keep in mind when working with WAR or EAR artifacts in IDEA is to deploy those artifacts as exploded ones!