There is a technique that can be used to overcome the infinite z-index of windowed controls, so that a div with a z-index greater than page level can be seen above the control, and the control does not show through (the classic problem). This fix involves shimming an iFrame under the div (for IE5.5+ only).
So far so good and it works well. Question is, if the control is a select box, this is hidden as it should be, but if the dropdown arrow part is showing outside of the div and then is clicked on, the list shows above the div and iFrame, just as though only the select box itself was hidden, and not the actual drop-down list.
Does anyone know why the rule is broken in this case and have a fix?