Added a passage about the new curios error, since the update to GWT 2.7

wiki/local-gwt.md

@@ -28,4 +28,10 @@ One of the great strengths of GWT is the use of Eclipse as a Java source-level d
 
 You can set breakpoints in your GWT Java code and inspect values for suspended threads as usual for any Java development.
 
-Note the reduced performance which is largely due to the way the Java VM and the browser plug-in communicate. In particular, many fine-grained changes to the DOM can be quite costly. Therefore, if you're only interested in server-side debugging, consider [compiling](#Local-GWT-Compile) the GWT code for better performance.
+Note the reduced performance which is largely due to the way the Java VM and the browser plug-in communicate. In particular, many fine-grained changes to the DOM can be quite costly. Therefore, if you're only interested in server-side debugging, consider [compiling](#Local-GWT-Compile) the GWT code for better performance.
+
+## Curious Errors
+
+There's a randomly occuring error, since the update to GWT 2.7, where an entry point fails to load. The Development Mode view of Eclipse shows the error  
+**Your source appears not to live underneath a subpackage called 'client'; no problem, but you'll need to use the <source> directive in your module to make it accessible**  
+The problem can be "solved" by retrying until it works.