- It sounds like another IE bug to me.
You might be able to have the onload event call a function hard-coded into the document. This function could then check to see if the required objects are loaded into memory yet. If not, it could set a timeout and call itself again and again every 100-or-so milliseconds until the either object is loaded or the function's called itself enough times that it would be prudent to give up.
Just a thought.