These are the ones which I installed. Is there anything missing or can there be a different version available? I reinstalled everything and added the references again (from Website--> Add Reference and also from bin --> right click Add reference), but still getting the same error.

Web.config reference (removed the greater than/lessthan symbols) given below:
add assembly="Mere Mortals Framework 2005 Infragistics Web Controls, Version=2.4.0.0, Culture=neutral, PublicKeyToken=F9B5AAF729361A44"

And this is refering to : "C:\Program Files\Mere Mortals .NET Framework 2005\Third Party Components\Infragistics Windows Controls\Mere Mortals Framework 2005 Infragistics Windows Controls.dll"

Build Error:
"D:\QIS\App\QISPortal\Web.Config(35): Build (web): Could not load file or assembly 'Mere Mortals Framework 2005 Infragistics Web Controls, Version=2.4.0.0, Culture=neutral, PublicKeyToken=f9b5aaf729361a44' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)"

Installations:
MM .NET 2.4 (for VS .NET 2005)
MM .NET Documentation
MM .NET 2005 Infragistics Windows Controls (2007 Volume 3 for VS 2005)
MM .NET 2005 Infragistics Web Controls (2007 Volume 3 for VS 2005)