Very curious as to whether disabling Headway's gzip output worked for @Bullrunner. I was working on a client site that had this same issue, found this thread, and decided to give it a shot. Here are the steps I took that have seemed to resolve the issue:
1. Disable Falcon.
2. Disable Headway gzip (go to Headway --> Options --> Advanced and then un-check the box for "Enable gzip compression").
3. Clear Headway cache (go to Visual Editor --> Tools --> Clear Cache). I am not sure if this was necessary, but I did it just in case it would make a difference.
4. Re-enable Falcon.
The blog is now displaying properly in the browser (although it seemed to display properly initially when I first enabled Falcon last night, so I'm not calling this a for-sure fix just yet). The page load time did drop by a few seconds, from 1.2 seconds last night to 5.94 seconds today, using pingdom's test.
I'm going to assume that disabling the Headway gzip optin IS a fix for this issue unless something suddenly goes awry, but I'll come back to update if that's the case.