Could not load file or assembly from Program files - W7

I installed my .Net application in to the Program files on Windows 7 machine. It was working perfectly. One week later i installed(now i have changed my certificate file key and signed my application. So that all assembly public key token value is different now) my application. When i tried to run my application, it threw the error message. " Could not load file or assembly 'microsoft.practices.enterpriselibrary.common, Version=2.0.0.0, Culture=neutral, PublicKeyToken=e7178be946f5d743' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference (Exception from HRESULT:0x80131040)

Then i look into 'Assembly Binding Log Viewer (Fuslogvw.exe)' . I found the following information

Code:

 
***************************************************************
*** Assembly Binder Log Entry (1/13/2010 @ 12:39:24 PM) ***
The operation failed.
Bind result: hr = 0x80131040. No description available.
Assembly manager loaded from: C:\Windows\Microsoft.NET\Framework\v2.0.50727\mscorwks.dll
Running under executable C:\Program Files\MyApplication\MyApplication.exe
--- A detailed error log follows. 
=== Pre-bind state information ===
LOG: User = IN\kmanassyed
LOG: DisplayName = Microsoft.Practices.EnterpriseLibrary.Common, Version=2.0.0.0, Culture=neutral, PublicKeyToken=e7178be946f5d743
(Fully-specified)
LOG: Appbase = file:///C:/Program Files/MyApplication/
LOG: Initial PrivatePath = NULL
LOG: Dynamic Base = NULL
LOG: Cache Base = NULL
LOG: AppName = MyApplication.exe
Calling assembly : System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a.
===
LOG: This bind starts in default load context.
LOG: Using application configuration file: C:\Program Files\MyApplication\MyApplication.exe.config
LOG: Using machine configuration file from C:\Windows\Microsoft.NET\Framework\v2.0.50727\config\machine.config.
LOG: Post-policy reference: Microsoft.Practices.EnterpriseLibrary.Common, Version=2.0.0.0, Culture=neutral, PublicKeyToken=e7178be946f5d743
LOG: GAC Lookup was unsuccessful.
LOG: Attempting download of new URL file:///C:/Program Files/MyApplication/Microsoft.Practices.EnterpriseLibrary.Common.DLL.
LOG: Assembly download was successful. Attempting setup of file: C:\Program Files\MyApplication\Microsoft.Practices.EnterpriseLibrary.Common.dll
LOG: Entering run-from-source setup phase.
LOG: Assembly Name is: Microsoft.Practices.EnterpriseLibrary.Common, Version=2.0.0.0, Culture=neutral, PublicKeyToken=89dbb42750bb6d3b
WRN: Comparing the assembly name resulted in the mismatch: PUBLIC KEY TOKEN
ERR: The assembly reference did not match the assembly definition found.
ERR: Failed to complete setup of assembly (hr = 0x80131040). Probing terminated.
***************************************************************

It says mismatch in Public Key token. Then i later found , my first certificate key value (using which i installed the application very first) to sign my application was "e7178be946f5d743". But now the application signed with the certificate(.pfx) that has key "89dbb42750bb6d3b". CLR Still looks for that e7178be946f5d743 assmeblies. If i install my application that signed with e7178be946f5d743 assembly it works fine. I cant run the application that signed with different key.

I have to add some interesting points here,

* If i right click my application.exe and click 'Run as Administrator', It prompts UAC prompt and after click 'yes' it works fine(Though I am admin to the system).

*My application works fine, If I install the application to any other local folder other than Program files

*My application works fine, If i turn off UAC

*Other assemblies like caching , servicemanager etc dlls were binded correctly

*I searched my whole system. i couldnot find the Microsoft.Practices.EnterpriseLibrary.Common.dll with public key token e7178be946f5d743 anywhere.

Anybody Advice me Pls. Thanks to read.