When I copy a state at least one of the symbols on the copied state disapear. I tried reinstalling fireworks but after a while the Problem appeard again.
I'm using the latest Version of Fireworks on a Mac (10.9.1). That's really annoying and time consuming.
I can confirm the same bug, though I believe the latest FW version is 12.0.1. Don't have any workarounds to offer — hopefully someone at Adobe will add this to their 'to fix' list, or someone else can offer a fix.
See a similar thread here: http://forums.adobe.com/message/5987155