I used sample code from DotNetOpenAuth.net to become my own OpenID Provider (OpenIDProviderWebForm) everything worked fine and I was able to test my OP against NerdDinner. now I want to customize the identifier like --->

http://www.mydomain.com/user.aspx/Hash(Username+PrivateKey)~Username.

everything works on OP side but on the NerdDinner application when the app tries to do

HttpRequestInfo clientResponseInfo = new HttpRequestInfo("GET", auth, auth.PathAndQuery, headers, null);

response = RelyingParty.GetResponse(clientResponseInfo);

(you find these two lines of codes in AuthController.cs from NerdDinner)

the response contains below error:

The OpenID Provider issued an assertion for an Identifier whose discovery information did not match.   
Assertion endpoint info:  
    ClaimedIdentifier: http://localhost:57571/user.aspx/76208371132EC7F7A37472C8B4CC2CC37A05B707~sohail 
    ProviderLocalIdentifier: http://localhost:57571/user.aspx/76208371132EC7F7A37472C8B4CC2CC37A05B707~sohail         
    ProviderEndpoint: http://localhost:57571/server.aspx
    OpenID version: 2.0
    Service Type URIs: 
Discovered endpoint info: [
{
    ClaimedIdentifier: http://localhost:57571/user.aspx/EA467E35736AC22EB60C04C2E9D9594263B60ECB~sohail     
    ProviderLocalIdentifier: http://localhost:57571/user.aspx/EA467E35736AC22EB60C04C2E9D9594263B60ECB~sohail   
    ProviderEndpoint: http://localhost:57571/server.aspx
    OpenID version: 2.0
    Service Type URIs:
        http://specs.openid.net/auth/2.0/signon
        http://openid.net/extensions/sreg/1.1
}, {
    ClaimedIdentifier: http://localhost:57571/user.aspx/EA467E35736AC22EB60C04C2E9D9594263B60ECB~sohail     
    ProviderLocalIdentifier: http://localhost:57571/user.aspx/EA467E35736AC22EB60C04C2E9D9594263B60ECB~sohail   
    ProviderEndpoint: http://localhost:57571/server.aspx
    OpenID version: 1.0
    Service Type URIs: 
        http://openid.net/signon/1.0
        http://openid.net/extensions/sreg/1.1
 },
]

anybody can help me please?