I've been looking through at people who have had the same issue, and the following solutions have been offered:
#top .sidebar2.sidebar_absolute {
margin-top: 100px;
}
and
#top.single .sidebar2 {
left: 888px !important;
}
However, neither really works for all pages/posts.
The first option does knock the sidebar down so it doesn't clash with the date box - but on pages (without a date box) the sidebar looks wrong as it doesn't align with the top of the page.
The second option merely moves the sidebar to the right, and that doesn't look good (for our site).
Can you suggest an alternative solution to get the sidebar to appear below the data box if it's there (on a post), but will appear level with the other areas (left menu and main content) on pages without the date box?