transitions not working in Windows 2000

This may actually be an old topic but since we just encountered it...I work in a large organization that still has some users on Windows 2000 machines. I don't know why, we just do. The problem is I get a call from a learner that text is not showing up for the course she's taking. (Windows 2000 5.000.2196 SP4)The developer set up the course so that text transitions in. Except on the learners machine the transitions never run. Running a script debugger on her machine I get an error message 'class not registered' and the debugger points to the line: this.ele.filters.revealTrans.apply() in the function: function ObjLayerDoTransIE()So is this a known problem with a workaround (other than taking the transitions off the course)? or a problem that gets ignored because they really ought to upgrade the OS anyway?Thanks, apprectiate the feedbackDavid Davis