Windows update KB2661254 blocks the use the use of RSA certificates that have keys that are less than 1024 bits long. 

During recording of secure traffic the recorder presents its own certificate rather than than the actual server certificate of the application you are recording to the browser (note it is not possible to forward the server certificate).  This recorder certificate contains an RSA key that is 512bits in length, therefore with Windows update KB2661254 applied, Internet Explorer blocks the connection.

The recorder certificate have been updated increasing the encryption key length with hotfix SP90_HF9_CERTS.  Please upgrade to the latest version of SilkPerformer to resolve this issue.