Web-start offers file access even to *sandboxed*
applications, assumimg the user approves each file.
There is a checkbox when opening 'always allow'
that seems to have no effect (on Win XP, Java 1.5).

I have set up a sandboxed application to test this,
and am trying to get more test results.

Further details are on the thread at ...
<http://forum.java.sun.com/thread.jspa?messageID=9424724&#9424724>
..but please check the later message for corrected URL's.
(Note that this 'repost on another forum' is almost two
months after the initial post, from which no results and
no comments were forthcoming.)

How does the application behave for you, does it
remember 'always allow'?  What OS/Java version
are you running?

Andrew T.