Hi Arlene - sorry you are having problems.
Can you open a support ticket with a user/pass for your admin side so I can take a look? Seems as if this is only happening with the internal player? I'm trying to figure out just what media settings you have.
To change the download image you actually need to go to the Administration tab and under System Defaults choose a different image. You can't change that setting from the Media Images. Honestly, I'm not sure why we did it this way, but at least that's where you change it!
Tom
This has been fixed in 7.0.4