It hurts me to say this. But google is a liar.

It tells you to insert their maps in the tag <iframe>. I expect google to be compliant with strict XHTML (not that it says this anywhere)

But this is not the case - because the iframe is not XHTML compliant.

Instead what you need to do is use the <object> tag and replace src=”” with data=”“.

This works fine on Firefox but then you have another problem -  It doesn’t work in ie6.

Internet explorer 6 has this funny little quirk where it recognizes an object tag as an active-x object.

The only solution appears to be wrap everything into a flash file and make your google map appear to ie6 like it is an active-x object

http://www.webmasterworld.com/forum21/10605.htm