异常详细信息: System.Runtime.InteropServices.COMException: 没有注册类别 - SDAVUtil（跪求啊！）

源代码：
reportDocument = new ReportDocument();
reportDocument.Load(Server.MapPath("CG_CGDD_Report.rpt"));
reportDocument.SetDataSource(ds);
ReportViewer.ReportSource = reportDocument;


错误提示：
[COMException (0x80040154): 没有注册类别 - SDAVUtil]
CrystalDecisions.ReportAppServer.ClientDoc.ReportClientDocumentClass.Open(Object& DocumentPath, Int32 Options) +0
CrystalDecisions.ReportAppServer.ReportClientDocumentWrapper.Open(Object& DocumentPath, Int32 Options) +95
CrystalDecisions.ReportAppServer.ReportClientDocumentWrapper.EnsureDocumentIsOpened() +271

[CrystalReportsException: 加载报表失败。]
CrystalDecisions.ReportAppServer.ReportClientDocumentWrapper.EnsureDocumentIsOpened() +334
CrystalDecisions.CrystalReports.Engine.ReportDocument.Load(String filename, OpenReportMethod openMethod, Int16 parentJob) +894
CrystalDecisions.CrystalReports.Engine.ReportDocument.Load(String filename) +84
Maticsoft.Web.Report.CaiGou.CG_CGDD_Report1.ConfigureCrystalReports() in D:\Printsoftwareweb\Web\Admin\Report\CaiGou\CG_CGDD\CG_CGDD_Report.aspx.cs:60
Maticsoft.Web.Report.CaiGou.CG_CGDD_Report1.Page_Init(Object sender, EventArgs e) in D:\Printsoftwareweb\Web\Admin\Report\CaiGou\CG_CGDD\CG_CGDD_Report.aspx.cs:72
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
System.Web.UI.Control.OnInit(EventArgs e) +99
System.Web.UI.Page.OnInit(EventArgs e) +12
System.Web.UI.Control.InitRecursive(Control namingContainer) +333
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +378

在编译状态下都正常，但是一在IIS中一运行就不行了，请问是什么问题？