Oracle RAC running mad

Excerpt:

CRS is used in conjunction with Oracle's Real Application Clusters 
software, which allows one Oracle database to be deployed on a group 
of servers or "nodes," providing fault tolerance and scalability.

The "leap second event" is causing CRS nodes to reboot, according to 
an Oracle document detailing the problem. Among the affected platforms 
are Oracle Server Enterprise Edition Version 10.1.0.2 to 11.1.0.7; 
Sun Solaris SPARC (64-bit); and Oracle CRS and patchsets 10.2.0.1 to 
11.1.0.7. 

I thought that one of the main reasons for setting up a database cluster is to increase availability and fault tolerance. It seems that Oracle missunderstood that :-) So what is the real meaning of the RAC abbreviation ?: