You have a lot going on in your TW. I'd guess you have at least a half dozen plugins. Nothing
wrong with that, but when you use multiple plugins from different authors it becomes
increasingly likely that some bit of CSS or other code will conflict with each other. Especially
when you're making major changes to the UI.
Off hand, I would try reverting the left hand column to right hand and see if the problem goes away.
Then turning off 2 columns and see if that fixes anything. Then work your way through the other
plugins. Try to determine which plugin is introducing
the issue. When you've determined which plugin is causing the issue, then find the author
and ask if they've seen the issue. Or repost the question in terms of the plugin so others who are
using that plugin can respond.
Hope you're feeling better!