Comment 3 for bug 1282305

Adam, are you sure that the window only gets shrunk vertically? Could it be that it gets shrunk horizontally, as well, but only to a rather small degree (as the window borders left, right and bottom are only a few or in some themes even 0 pixels)?

It could have to do with the size of the window decoration, as you noted in your linked bug report. Then of course it would be way more prominent in regards to changes to the vertical window size with a usual title bar size of 24 or so pixels. In that case, several other bugs might be related to this issue, as well: bug #1204307, bug #1287472 and others