I just received an email with the link to this bug in Java. Incredible, by now it is only fixed in the 1.5 JDK – it really seems that Sun wants us moving to Mustang (Java 1.5/ 5.0) at any price…
As far it is described in the bug report/ comments, Sun’s JDK is calling the wrong Windows function to create files. The one used can only handly 32k sized filenames (incl. path).