If you can't get it to work, try doing everything in this thread:
And everything here:
Also, SSRS 2008 does not support wildcard certificates, ie *.yourdomain.com. Obtain a special dedicated SSL cert YourServerName.yourdomain.com, then apply it on the SSRS 2008 server. This is what worked for us at a client, after calling PSS. This is a known issue at Microsoft and they are working on a better solution.