When you use authenticode signed assemblies in an application, the application needs to go out and check the certificate revocation lists (CRLs) to verify that the signature is still valid the first time it loads up the authenticode signed assembly.
If the server, serving your asp.net application, doesn't have internet access or if the internet connection is slow this can lead to issues where you stall the process during startup or when the assembly in question first loads.
What you will typically see is a thread loading up an assembly with a callstack like this:
0:026> kL 200
ChildEBP RetAddr
0e82c1b4 7c822124 ntdll!KiFastSystemCallRet
0e82c1b8 77e6bad8 ntdll!NtWaitForSingleObject+0xc
0e82c228 73ca64ec kernel32!WaitForSingleObjectEx+0xac
0e82c254 73ca6742 cryptnet!CryptRetrieveObjectByUrlWithTimeout+0x12f
0e82c280 73ca ...
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