Marco, did you find a solution to this problem.
We too are encountering the same issue.
Make GET requests to static content instead of bodyless POST requests.. I think the only way to do this at the moment is to map a filter to the default servlet that wraps the request and changes the method to GET
It seems that HTTP method POST for .html file is not supported default on JBoss which is different from other servlet engines.
See this thread: https://developer.jboss.org/thread/272005