I tested following your steps and was able to reproduce the issue. I was able to work around this by deleting the test1 div and then adding it again. The divs then work again as they should. Let me know if that works for you.
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.