Cannot create class-file

Hi

I'm starting with intellij idea (community edition) and Scala. I followed the hello world example for scala (http://confluence.jetbrains.net/display/SCA/Getting+Started+with+IntelliJ+IDEA+Scala+Plugin).
I created a scala project, created a package in the src dir (works) then i tried to create a class file in the package (right-click on the package - new - scala class). Then there is a popup "Create New Scala Class" I enter the name "HelloWorld" and the type "object" press OK and get the message "cannot create class file" and thats it, nothing happens.


I tried to set this up on another computer to see if it's local to this machine, and it is. Everything works fine on another computer (same JDK, same Scala version).
Any ideas anyone?


Thanks
Michael