Hi John T. I am a bit new to all of this. By latest build....do you mean am I using the latest version of MC?
Yes, click "Help" on the menu and "About Media Center" and it will tell you at the top of the pop-up what build (version) you're running. You can click "Help / Update Channels / Check for updates" to get the latest version. Make sure "Disable automatic update" is NOT checked. If your version is 175 or greater, you should be fine.
I did change rip settings from secure to normal and I have been able to rip some of the problem CDs but not all.
Do the problem discs have a lot of scratches? Sometimes cleaning them helps. Try dropping the "read speed" to 1x (the option is next to the "secure" vs. "normal" rip mode you changed.