Steps to Reproduce

similar example as ZK-5000 just add a combobox to the new row zk-5001.zul

click the plus button in any row

Current Result

UI freezes for a long time (here 13 seconds) while updating the link labels

This effect multiplies with more complex grids

Expected Result

avoid long UI freezes

Debug Information

adding a single empty combobox (no children) affects the update duration dramatically.
this doesn't happen with a textbox (commented out in the example, or when removing the combobox)

Workaround