Sidebar Shifted to bottom of content

My site appeared to be working fine, but the day it went live, the sidebar decided inexplicably to shift to the bottom of the content. I have seen this problem discussed in similar posts, but the fixes noteded there do not seem to be applicable here. Interestingly, on some computers the sidebar is shifted on all of the pages, and on other PC’s (using the same version if IE) only one page is shifted. The site is https://www.furnacehills.com. The page that is always shifted is https://www.furnacehills.com/specials
Any help would be appreciated.