Unable to install outlook plugin - not a valid office Add-in.

Unable to install outlook plugin - not a valid office Add-in.

I am using Outlook 2010 64 bit on Windows 7.
I have downloaded the 64 bit edition, and it installs successfully.

C:\windows\system32>C:\Windows\Microsoft.NET\Framework64\v2.0.50727\RegAsm.exe "
C:\Users\Vinai\AppData\Roaming\ZOHO\zohocrm\ZohoCRMOLAddin.dll"
Microsoft (R) .NET Framework Assembly Registration Utility 2.0.50727.4927
Copyright (C) Microsoft Corporation 1998-2004.  All rights reserved.

Types registered successfully

C:\windows\system32>regsvr32 "C:\Users\Vinai\AppData\Roaming\ZOHO\zohocrm\Redemp
tion.dll"

But when I go into Outlook, I do not see the ZohoCRM bar. Under Add-Ins, I do not see any Addin for Zoho.
When I click Add-ins, Go, and try to addin the DLL file manually, it says

ZohoCRMOLAddin.DLL is not a valid office Add-In.

My email is vinai@pmchamp.com

Thanks,
Vinai