After the recent announcement of security vulnerabilities in CB 1.0 and 1.1, I decided to upgrade a couple of old J1.0.15/VM1.0.15 sites to CB 1.2.1. When I did this, it adversely affected the Virtuemart plugin.
After much searching, I found this post that solved most of my problems:
www.joomlapolis.com/index.php?option=com_joomlaboard&Itemid=38&func=view&catid=64&id=79512
So fabf, if you're still out there, thanks a million! You helped me greatly!
My one remaining problem is that the CB regis form is not displaying on the VM checkout page for non-logged-in users. I have temporarily addressed this by modifying the VM language file to add a link to the CB registration page in the line that says, 'New? Please provide your billing information.' But if anyone knows the proper fix to display the fields on that page, please advise.
Thanks!