Conflict between CB Player with JW Player, This happen only if they are on the same page and only if those two one have the adsolution activate, This issue come from longtailvideo, we wait from them a solution.
Also you can check the active ticket on longtail :
by the way it's not suffisant for us, the cause is that a script is loading before the page finish to load, the solution for that is to adjust the loading a windows.onload function, we work on this.