Yahoo Maps and contrain resize

I'm trying to resolve a problem where my yahoo map disappears on page load. The master page runs a script to resize the content div so only that portion of the page will display a scrollbar. This give us a static header that doesn't move while the rest of the page can scroll. The problem I am seeing is that the map is drawn, but as soon as the resize script runs the map disappears.

I have tried redrawing the map with drawZoomAndCenter and resizeTo, but no luck. The site uses master pages and updatepanels. Has anyone else run into this problem or have any ideas on a workaround?