Sidebar not appearing

Hi,
i’m a noob and dumb so be gentle.
I’m running the 2011 theme for a new site here but i’m not able to add widgets to the sidebar.
They do add to the footer area ok.
I’ve searched the support forum and so added widgets (a calender by way of testing) to the main sidebar and showcase sidebar.
I’m using firefox, have cleared cache and also checked on a machine using Crome but still no sidebar widgets.
I did have, but removed, the add sidebar widget. Any ideas would be really welcome.
Thanks in advance.
Stup’