If the user surfs away from the search while the search is still in progress (i.e. the datasets are already found, or he/she wants to narrow the search further) the Gateway shows a popup with a "Communication Error" message until the new page is loaded.
The slower the connection the longer it takes the popup to disappear (try it with a Gateway that's laying on the other side of the Atlantic and you'll see what I mean :-)

The connection should be aborted/canceled when going away from the page silently (just like when closing the popup while searching)