Real Studio 2012 Release 1 makes use of the updated plugins API. In addition, some older classes that have been deprecated for a while have been removed (such as ContextualMenu).
This means, more so than past releases, you also need to make sure you are have installed the latest versions of any plugins that you use.
Older plugins that may still be relying on no longer supported API calls or removed functionality. This could cause them to behave unreliably and possibly cause instability when used with 2012r1.
For your reference, here are links to popular plugins used with Real Studio: