Hi.
There is a bug somewhere in the JNLP download servlet that comes with the JDK. If you're using that, it is possibly due to this bug.
I am searching now for a forum thread either here or at java.sun.com with discussion of this. I can't find it!
If you;re using that servlet, turn on an HTTP request monitor while fetching your JNLP file. The servlet is doing something like re-downloading all of the jars every time a check happens: it connects with the server, and the code in or around version checking results in the jars downloading on every request.
Someone made a modification to incorporate last-modified-date checking; but I don't know if that wound up breaking the semantics of the versioned download (because I can't find this thread now!).
There is also now a project at java.net which seems to have this servlet's code in it. Perhaps you can peek in there and contribute anything you might find. I will have to be looking into this very soon, and I'll likely root through that code base to become satisfied that the servlet is behaving correctly.
Hope that helps.
Ciao.
Steven Coco.
[Message sent by forum member 'steevcoco' (steevcoco)]
http://forums.java.net/jive/thread.jspa?messageID=220904