Now I feel stupid or like Im losing it, but I went back and grepped for the CONFIG_FILE_LOCKING in my old Configs, and it was turned on in all but 6.6.9. So, somehow I turned that off *after I built 6.6.9? Argh. I just built 6.6.4 with it unset and that locked up too. Sorry if this is just noise, though one would have hoped the failure was less severe...

Paul