It sounds like what you're running in to is a bug. Unforunately, the VideoPlayer was still being worked on as beta1 went out the door, so there might be a few of these bugs lying around. I'd encourage you to download a new nightly build and try it out on trunk and/or file a bug (or post your code here).
Nightly builds of the Flex 4 SDK can be downloaded from the Adobe Open Source site at http://opensource.adobe.com/wiki/display/flexsdk/Download+Flex+4
Also, bug files (and feature/enhancement requests) can be filed at http://bugs.adobe.com/flex/ (bonus points for submitting a simple test case along with the bug).
Flex SDK Team | Adobe Systems Inc
Peter and Ryan,
Just a posted a bug with some sample code. Thanks for your help.