Select and use Clean theme throughout these tests: Note that this is only a regression testing. Margins should look the same before and after this patch. TEST A - three column layout (includes the Secure layout) Login and go to the Frontpage and make sure that there are at least three blocks displayed correctly either side of the main content. Check also to see that the blocks on the left are equally spaced from the edge of the page to the side of the browser window, as they are on the right. TEST B - two column layout. Go to Site Administration > Notifications and verify the page is set out as it should be with blocks on the left. PLEASE NOTE: Since this test will require testing in RTL it may be easier if you understand the way the blocks work. So 'Pre' in this case mean 'before main content' and so in RTL (Right to Left) Pre will be on the RIGHT. So what is happening in the layout, is that the containers carrying the 'side pre' blocks, slide from left to right. There's no JavaScript trickery here! It is all done with CSS. Change language to a RTL one like Hebrew or Arabic and check that the column that was previously on the left is now on the right but displayed correctly with a margin between the main content and the blocks and also from the blocks to the edge of the browser window.