Crystal Reports Compilation Error after upgrading

Message

     We removed Crystal reports 10.2.3600 and installed the newer 11.5

However there are still lots of referances to the old version in the registry.  Im a bit causion about us just deleting these referances.

The problem is, we have cjhecked an dtripple checked that there are no referances to the old version in our code, but we get the following error :

[quote]

Compilation Error 
Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. 

Compiler Error Message: BC30560: 'CrystalReportSource' is ambiguous in the namespace 'CrystalDecisions.Web'.

Source Error:

Line 36:     </asp:DetailsView>
Line 37:     <br />
Line 38:     <CR:CrystalReportSource ID="CP12InfoSource" runat="server">
Line 39:     </CR:CrystalReportSource>
Line 40:     <asp:Button ID="btNewWO" runat="server" Text="New Workorder" Font-Bold="True" Font-Names="Tahoma" Font-Size="11pt" />&nbsp<asp:Button ID="btEdit" runat="server" Text="Edit CP12" UseSubmitBehavior="False" Enabled="False" Font-Bold="True" Font-Names="Tahoma" Font-Size="11pt" />

Source File: D:\web\SMax\CustInfo.aspx    Line: 38  {/quote}

Is it safe to remove these registry entries ? if so is it likley to fix the problem?  any other suggestions ?

Thanks.