ASP.NET MVC - Current Selected value doesnt get selected in IE - asp.net-mvc-3

Question

In my Action for Editing an item in my model I have:
ViewBag.PossibleSource = context.Source.ToList();
In my View I have:
#Html.DropDownListFor(model => model.SourceID, ((IEnumerable<btn_intranet.Areas.DayBook.Models.DayBookSource>)ViewBag.PossibleSource).Select(option => new SelectListItem
{
Text = (option == null ? "None" : option.SourceName),
Value = option.SourceID.ToString(),
Selected = (Model != null) && (option.SourceID == Model.SourceID)
}))
In Chrome this works as expected. When I pass a model to my view, the current value that's set in my model is the selected value in the list. But in IE8 and 9 it's selected value is the ORIGINAL value my model was set as even though the update does work. So if I selected "hello" originally and then edited to "world". In chrome when i reload the page it will be set to "world" but in IE "hello" is selected in the dropdown even tho "world" is set in my database for my model. It is worth noting these are updated via AJAX
EDIT:
Ajax.Actionlink:
#Ajax.ActionLink(item.ItemNumber, "EditItem", new { id = item.QuoteLineID, enquiryId = item.EnquiryID }, new AjaxOptions()
{
InsertionMode = InsertionMode.Replace,
UpdateTargetId = "EditItem"
})
This loads the form onto the view.
Ajax.BeginForm:
#using (Ajax.BeginForm("EditItem", new { controller = "QuoteLines" }, new AjaxOptions()
{
InsertionMode = InsertionMode.Replace,
UpdateTargetId = "Summary"
}, new { #class = "manual-search cf" }))
{
...Other Model inputs
#Html.DropDownListFor(model => model.SourceID, ((IEnumerable<btn_intranet.Areas.DayBook.Models.DayBookSource>)ViewBag.PossibleSource).Select(option => new SelectListItem
{
Text = (option == null ? "None" : option.SourceName),
Value = option.SourceID.ToString(),
Selected = (Model != null) && (option.SourceID == Model.SourceID)
}))
<input type="submit" class="update-items" value="Update Line" />
}
EditItem Action GET request:
public virtual ActionResult EditItem(int id)
{
try
{
DayBookQuoteLines q = context.QuoteLines.Single(x => x.QuoteLineID == id);
ViewBag.PossibleSource = context.Source.ToList();
if (Request.IsAjaxRequest())
{
return PartialView("_EditItem", q);
}
else
{
return RedirectToAction("SalesDetails", new { controller = "Enquiries", id = q.EnquiryID });
}
}
catch (Exception ex)
{
return PartialView("_Error", ex.Message);
}
}
EditItem Action POST request:
[HttpPost]
public virtual ActionResult EditItem(DayBookQuoteLines q)
{
try
{
ViewBag.PossibleSource = context.Source.ToList();
if (ModelState.IsValid)
{
context.Entry(q).State = EntityState.Modified;
context.SaveChanges();
return PartialView("_GetSummary", context.Vehicles.Where(x => x.EnquiryID == q.EnquiryID).ToList());
}
return PartialView("_EditItem", q);
}
catch (Exception ex)
{
return PartialView("_Error", ex.Message);
}
}

Answer 1

I've fixed it, I renamed my GET request for EditItem to EditItemGet and then in my #Ajax.ActionLink I did:
#Ajax.ActionLink(item.ItemNumber, "EditItemGet", new { id = item.QuoteLineID, enquiryId = item.EnquiryID }, new AjaxOptions()
{
InsertionMode = InsertionMode.Replace,
UpdateTargetId = "EditItem",
HttpMethod = "POST"
})
It was a Cache issue. Thats why it only failed in IE which likes Cache. I read before that making the request a POST request prevents Caching.