This recording illustrates extreme buffer delays in IE11 that do not occur in Chrome. Verified on multiple systems, even on Server 2008 R2. IE11 appears to buffer the entire clip pre timeline insertion point before it will begin playback. With delivery at 30mbps max and common lecture duration over one hour, it can take minutes before playback will begin. Any screen resize will abort playback and switch to an "appropriate" resolution flavor as set in the KMS, forcing yet another complete re-load of the clip. Even when downsizing, the entire buffer is emptied and the browser will reconnect at the lower flavor resolution, causing again extended delays. Chrome does not exhibit any of the buffering behavior - it appears to just buffer a minimal segment prior to playback, so resolution switches are also barely an issue for the viewer, even though it does switch qualities just like IE11. Apart from that, IE11 loses control over the volume slider in full screen - only mute/unmute are available, and if you click on the volume adjuster slider, it will move to 0%. Only keyboard cursor control allows volume control in IE11 full screen. This bug has been present for many months in all HTML5 players we have seen. The buffering issue persists across KMS, KAF and remote embedded players, as long as the service is set to use progressive download.