That seems to be the same problem as the previous report. Could be a problem with Webstart itself. I suggest trying to clear webstart's cache. To do that open start jcontrol (located in the bin directory of your Java installation directory). This should open a window with several tabs. On tab "General" should be section "Temporary Internet Files" with a button "Settings...". Clicking that button opens a dialog which lets you "Delete Files...". Alternatively, using the "View..." button next to "Settings..." opens the cache viewer which can be used to delete specific files only.