Why won't Flash Builder install?

I am attempting to update my Adobe CS5 to Adobe CS6.  Everything is fine until I get to this screen:

So, following the instructions, I completely removed Flash Builder from my computer and emptied the trash bin.  I relaunch the install, and it still tells me there is a conflicting version.  I tried restarting my entire computer and still have nothing.  Now I have no Flash Builder at all on my computer and the installer refuses to let me click it as an install option.

This is extremely frustrating and Flash Builder is a program that I absolutely need.  I don't want to install anything else until I can figure this out because I don't want the download to be a one time shot and then I'm completely out of luck.  Any help would be greatly appreciated before this beautiful Macbook Pro becomes a frisbee!