Deleting a file from a JWS app

We're facing a strange behaviour when we try to use java.io.File.delete() on a file that was not created by our app. When it is run from an IDE, the files are deleted as expected. However, when the app is packaged and launched from JWS, some of the files do get deleted and some don't - we can't see any pattern in it.

What might be the reason?

The jars of our app are signed by a code-signing certificate from Thawte. The Java version is 1.5.0_08.

[470 byte] By [maxipesa] at [2007-10-3 4:30:38]