Windows server 2008 IIS 7 with SSL and ASN1 bad tag value met
Anyway I was following the steps provided when I bumped into this:
It's actually a known issue and is described here and what to do about it:
Note: There is a known issue in IIS 7 giving the following error: "Cannot find the certificate request associated with this certificate file. A certificate request must be completed on the computer where it was created." You may also receive a message stating "ASN1 bad tag value met". If this is the same server that you generated the CSR on then, in most cases, the certificate is actually installed. Simply cancel the dialog and press "F5" to refresh the list of server certificates. If the new certificate is now in the list, you can continue with the next step. If it is not in the list, you will need to reissue your certificate using a new CSR (see our CSR creation instructions for IIS 7). After creating a new CSR, login to your DigiCert account and click the reissue button for your certificate.
It was actually easier in my case as I already had the pfx exported from the IIS 6 server but still an error like this coming up on a brand new server is not confidence building.
All in all I think MS did a decent job with IIS7 and SSL and its less confusing then IIS6 and I now have my CF9 Flex app running behind SSL.