I have use web Combo with UltraWebGrid on my asp.net page and the tag registraion shows like this 

<%@ Register Assembly="Infragistics2.WebUI.WebCombo.v8.1, Version=8.1.20081.1000, Culture=neutral, PublicKeyToken=7dd5c3163f2cd0cb"
    Namespace="Infragistics.WebUI.WebCombo" TagPrefix="igcmbo" %>
<%@ Register Assembly="Infragistics2.WebUI.UltraWebGrid.v8.1, Version=8.1.20081.1000, Culture=neutral, PublicKeyToken=7dd5c3163f2cd0cb"
    Namespace="Infragistics.WebUI.UltraWebGrid" TagPrefix="igtbl" %>

 for the grid and combo

 but combo column declareation intellicense not work on asp.net page, but when i change Tag

 TagPrefix="igtbl" to TagPrefix="igcmbo" intelisense start working, but problem is then grid won't work, and when i got the page design mode and open webcombo column editor column get reset to defaut control layout, i can't create the columns and edit it. what is the solution for this matter

thanx charaka