Issue: Post problems

I'm having a problem with the options for editing/customizing my post. I can't change text colors, sizes, or fonts. None of the drop menus are working for me and I can't use the link buttons, etc. This starting happening when you guys were working on the site changing the layout and putting in the ads, etc. Is this a problem on my end? I'm not sure if I need to update something or what. I'm just wondering if my internet explorer is no longer compatible or if I'm having a problem with the javascript. Any help would be appreciated.