I have used a Spry Accordion and inserted flash animations and flash video in various panels.
Firefox and Google Chrome both stop the video/animation on closing the panel then restart it on re-opening.
However IE keeps it running. So if i have a flash animation that is set to stop after running so many frames on closing and re-opening the panel it remains on the last frame.
Appendix 1, Appendix 4, Appendix 5 at www.monkeyplaytest.co.uk