I've got combobox inside some panel :
<ajaxToolkit:ComboBox
ID="YearList"
runat="server"
OnInit="YearList_Init1"
EnableTheming="false"
Width="45px"
ViewStateMode="Disabled" />
and it was OK before I updated project to .NET 4 , after updating project (And AJAX) to .net4 it's looking like really strange ... I can't explain it proper , I will show :
how can I fix it ? :) Full CSS / ASPX page here -> https://github.com/nCdy/Issues/tree/master/Ajax%20ComboBox (string # 287)