By the way, here's a follow up: The problem that started this thread was caused by my misunderstanding of the way the <object> tag works.

Here's how the tag reallly works:

<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" ...>
... is for Internet Explorer on Windows only and will render and function only the ActiveX version of a Flash file.

<object type="application/x-shockwave-flash"...>
... this works on browsers that do not use ActiveX controls. Such as Firefox and Safari.

So if you encase something in the IE version of the object tag, whatever is inside that IE object tag is gonna get rendered on any browser that's not Win/IE. In my case, the thing that I had encased was an <embed> as well as the Alt text. It's no wonder they both got rendered.