I know this question is almost one year old, but it's on page one on Google, so maybe I can help someone.
For me it's a graphic tablet driver by Wacom that seems to interfere with Fireworks on startup while loading the keyboard shortcuts. After killing the driver's task in the task manager Fireworks starts up normally.
I JUST had this same exact issue and THANK YOU for pointing out the Wacom driver. That did the trick! I was pulling my hair out!