Every time I edit a WordPress post or page that has a google map embedded in it - useing the "visual" edit mode - wordpress deletes part of the data.
for example: this
<iframe width="425" height="350" frameborder="0" scrolling="no" marginheight="0" marginwidth="0" src="http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=212526618623367333770.00049b7dc074f6426719d&t=h&ll=34.926059,-81.964874&spn=0.300106,0.458336&output=embed"></iframe><br /><small>View <a href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=212526618623367333770.00049b7dc074f6426719d&t=h&ll=34.926059,-81.964874&spn=0.300106,0.458336&source=embed" style="color:#0000FF;text-align:left">1825 Spartanburgh Map</a> in a larger map</small>
turns into
<small>View <a style="color: #0000ff; text-align: left;" href="http://maps.google.com/maps/ms?ie=UTF8&hl=en&msa=0&msid=212526618623367333770.00049b7dc074f6426719d&ll=34.926059,-81.943846&spn=0.300106,0.416279&source=embed">1825</a> in a larger map</small>
Which does not render the map at all.
This does not happen when I edit in "html" mode.
How can I prevent Wordpress from altering this embed code?