Can you provide more details when you say it "locks up"? What page are you on, what are you trying to do, etc. Also, what version of Firefox and OS are you on?
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.