System.Reflection.TargetException: Object does not match target type.

Hi

I am getting this error when i bind ultraweb grid in 1.1 framework infragistices version 6.3

Stack Trace:

[TargetException: Object does not match target type.]
   System.Reflection.RuntimeMethodInfo.InternalInvoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean isBinderDefault, Assembly caller, Boolean verifyAccess) +0
   System.Reflection.RuntimeMethodInfo.InternalInvoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean verifyAccess) +320
   System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) +23
   System.Reflection.MethodInfo.Invoke(Object obj, Object[] parameters) +17
   Infragistics.WebUI.Misc.RenderUtils.CssStyleClass.GetFilteredStyle()
   Infragistics.WebUI.Misc.RenderUtils.CssStyleClass.GetAttributesString(WebControl control)
   Infragistics.WebUI.Misc.RenderUtils.CssStyleClass.WriteClass(String uniquePrefix, TextWriter writer, WebControl control)
   Infragistics.WebUI.Misc.MiscRenderBase.WriteCssClassesAndRegisterGenerics(TextWriter writer)
   Infragistics.WebUI.Misc.MiscRenderBase.GetAllClassesAndRegisterGenerics()
   Infragistics.WebUI.Misc.MiscRenderBase.RegisterAllCssClasses()
   Infragistics.WebUI.Misc.WebPanel.Render(HtmlTextWriter writer)
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   System.Web.UI.HtmlControls.HtmlForm.RenderChildren(HtmlTextWriter writer)
   System.Web.UI.HtmlControls.HtmlContainerControl.Render(HtmlTextWriter writer)
   System.Web.UI.HtmlControls.HtmlForm.Render(HtmlTextWriter output)
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
   System.Web.UI.Control.Render(HtmlTextWriter writer)
   System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
   System.Web.UI.Page.ProcessRequestMain() 

Please suggest me to fix this