Update - I found in my user account how to load an older firmware. So I changed back to 1.6 on the SL24 only and everything now works fine. Then I tried updating to the current 1.7 and immediately the locking up problems returned. So I'm sticking with 1.6 for now, until I can figure out the issue.
In anyone has experienced this issue, I'd like to know more about how they resolved it. I'd like to take advantage of the new features in 1.7