Steps to Reproduce

open zephyr-test/mvvm/book/databinding/childrenbinding/children-simple.zul
follow the steps

Current Result

3. click "reload 2" button:
you should see Item A, B, C, D (4 items) are added into "Simple - load after cmd".

Expected Result

(same as the case in zktest)
3. click "reload 2" button:
you should see Item A, B, C, D, E (5 items) are added into "Simple - load after cmd".

Debug Information

shall refine web driver test case