I upgraded CB 1.0RC2 to CB 1.0Stable and all is working normally.
Upgrade process with a load of plugins already installed went very smoothly. I had to manually delete the old comprofiler files as the ownership was different than Joomla's Installer.
If you care upgrading to Joomla 1.0.10, you should care upgrading to CB 1.0 stable for same reasons (security fixes).
When we did interoperability tests as we do with each Joomla core release with core team before Joomla or CB releases, it was checked with CB 1.0 stable, and probable that earlier versions (RC2 and before) would not work anymore. This is good, because the CB 1.0 stable update is highly recommended.