There are so many versions of the JRE out ... that should tell you something. I'm personally running 1.5.0_02. When the content locks up ... is it during your "close" of the content ... during your posting of test results ... or just normal navigation. When the lockup occurs can better point to what the issue is:1) close - could be the way the LMS is handling the polling of the window and the refreshing of the status in the LMS.2) posting of test results - could be the interactions data 3) normal navigation ... who knows ...There are some debugging things you can do ... unfortunately, almost anything you do to debug changes the timing of the situation and thus it can either exacerbate the problem ... or mask it.Tim V