Hi Bill,

BS> I don't think this is an error. Upekkha is the attainment
BS> of the third jhana. In the fourth jhana, upekkha is
BS> stilled, so attention to upekkha becomes a hindrance.

Thank you. Indeed I have found a confirmation in Tapussa sutta

http://www.accesstoinsight.org/canon/anguttara/an9-41.html

Metta,
Dimitry