I'd like to ask you for details here - can you please share more about the exact problem you get? Do you get a failure on execution? You can quickly record a short video to demonstrate the problem using Jing
The build my colleague pointed you to is an internal build. You can also download the latest one from your account and give that a go.
This is close to being promoted as official build in the next two or three weeks. If there is still a compatibility issue with latest Firefox we'd definitely like to isolate and address it in time for the official one.
I'm looking forward to hearing from you.