JQuery :: Saving The State Of An Ajax Form?

I have a page with a simple form: 3 hidden fields and 3 selects. I load the data for the first select via Ajax on domready. I have "change" event handlers for all 3 fields. If I select something in the first select, the corresponding data gets loaded into the second select via Ajax etc. So it's a "cascade" of selects. When an option in the 3rd select is being selected, I save the values of all 3 selected options in the hidden fields, and create a button for submitting the form. Until here everything works fine. When a users hits the submit button, he is being forwarded to a results page. Now, when the user hits the back button, and the page with the form gets loaded again, I check if the first hidden field has a value. If so, I try to fill all the form fields with the values the user had entered (i.e. the selections he made), which means I make 3 Ajax calls (to have all the data available), and mark the options the user had selected as selected. That works fine in FF 3 and 3.5, Safari 4, as well as IE 7 right now. IE 6 only display the data of the first select (as if the other two Ajax calls aren't successful or something - no errors though), while Opera 9 doesn't seem to remember the values of the 3 hidden fields (same issue with IE 8, but I'm using IE Tester, which is not always reliable). The html and jquery code (leaving out all the details) look like this:

<form id="myform" action="action.php" method="get">
<input name="manu_saved" id="manu_saved" type="hidden" />
<input name="series_saved" id="series_saved" type="hidden" />
<input name="type_saved" id="type_saved" type="hidden" />

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