ORA-07445: kkestJoinSelFlag

One of the data warehouse (11.2.0.1.0) database is repeatedly showing an exception every other day. I used 7445 tool in finding a note in MOS. I came across ORA-7445:[KKESTGETCOLGROUPNDV()+160] with nightly SQL tuning advisor job [ID 1268227.1]The above document suggest the following solutions:
2) For 11.2.0.1:
apply patch 9081848 for your platform.
Workaround:
----------
SQL> Alter systne set "_optimizer_enable_extended_stats" = FALSE;

Note: workaround disables extended statitcs 11g functionality at database level, while effect of the error is limited to a failure of a specific automatic SQL tuning Job and not to typical application queries.

Patch 9081848 is not available for Solaris platform. Is it safe to apply the above workaround? Did someone already resolved the same issue earlier? What are your suggestions?