It's because of your moving pictures logo in the top of your descriptions.

If you can work out what part of the HTML code is that part and remove it or replace it with a static logo then apply it to all listings you will be ok.

For example if you go to revise a listing and select HTML at the description you then copy n paste it into a graphics HTML code converter tool you can then change the moving logo to a static one or remove it.

Then re-apply the new HTML code to the listing.

And you should be able to bulk edit the description to apply the new code.

It's not too difficult if you are good with computers but a little complex if not and perhaps getting a web graphics person onto it may be a good idea. It doesn't matter if it is not the original designer, this change is very quick and easy for a pro.

What reason have they given for removing all your listings?

You don't have any active content that I have seen.

kopenhagen5 is correct about the moving picture logo.  It is actually what is called a Shockwave Flash Oblect along with some javascript which are active content.  Without seeing your html it a bit hard to say what to remove but you will probably have something like

<Object "width"=123 "height"=456 blah blah blah blah>
<param names>  be a whole pile of these
<embed name>

</Object>

Delete everything from <Object> ... </Object> including the <Object> tags and replace with an image eg

<img width="650" src="http://i248.photobucket.com/albums/gg187/babytoddlerchild/tutu/P1010852.jpg" border="0" hspace="0">

Note: the above removes your animation and replaces it with a still picture.  To replace with something like an animated photo gallery without active content can be done with CSS3 and HTML5 but is way past a short explanation here.

As for removing all your ads my understanding was that at least initially active content would just be disabled, so buyers would just see a blank where your animation is located.  However the problem arises when you try to relist or upload a new item, eBay will probably block it uploading until the active content is removed.

PS Your Sellathon at the bottom is also active content.