If "Save on Loss of Focus" is enabled, and I make a change and then alt-tab (i.e., I'm copying/pasting content from a query window into some XML), SE re-grabs focus doing the save operation.
So, instead of SE alt-tab query alt-tab SE, it's SE alt-tab alt-tab query alt-tab SE.
If I a) don't make a change; or b) make a change but have save on loss of focus disabled, it doesn't do this.