Cool thanx for the info. Then I guess I have no need for the jnlp file for the moment.
Is this true even in the case of arguements passed with a"jnlp" script?
yes in some ways it is true, jnlp will work but... first it is jnlp you will got other problem and it may not run as expected :
1 - not using standard applet tag and can have server issue (jnlp mime type) as client plugin issue
2 - the jvm argument must be set before the vm is started, prior to java 1.6 there was only one instance of the jvm, It maybe possible that parameter is only working if no "applet" have been run before your applet .
about the applet tag, even if it is a little outdated (my side I believe it is still more robust than any other object tag):
Note: The HTML specification states that the applet tag is deprecated, and that you should use the object tag instead. However, the specification is vague about how browsers should implement the object tag to support Java applets, and browser support is currently inconsistent. Sun therefore recommends that you continue to use the applet tag as a consistent way to deploy Java applets across browsers on all platforms.
source : http://java.sun.com/j2se/1.5.0/docs/guide/plugin/developer_guide/using_tags.html#applet