The error you describe can come from one of two places. First, the technote you mentioned above where you turn off the CRL check within Internet Explorer fixes a timeout that can occur. Be sure that you're logged onto the Sharepoint Web server with the account used for backup when you perform those steps in IE, otherwise it won't work. Second, as the error message indicates, a query to Sharepoint for the active web servers provides a list that doesn't include the web server used. This can be caused by a couple things. We've seen the web server misspelled within Sharepoint causing the mismatch. Also, if you have Sharepoint configured to use FQDN server names, the comparison won't work with the local machine name. This second issue was fixed with the release of Backup Exec 2010 R3. See http://www.symantec.com/docs/TECH87062, http://www.symantec.com/docs/TECH148401
Russ