Sidebar disappeared on home page

For some reason on my site at HighTechrealm.com the sidebar on my blog homepage has disappeared however on the individual blog posts, the sidebar is showing properly.

I’m not sure if it has to do with my WPMU plugins being out of date – however if so I’ve been unable to update them because the WPMU Dashboard has been causing the white screen of death so I had to remove it awhile ago.

Thanks in advance for any insights,

Charles