According to my PPC documentation Rev Ruling 81-152 reads in part:
"To the extent capital assessments are, or have been made against the unit owners for the purpose of making the necessary repairs or replacements, or the association retains the amounts recovered in the suit against the builder and uses them for capital repairs, replacement, or improvements, the unit owners' bases, under Section 1016, will be increased."
I have always maintained that capital assessments increase basis. However, this assumes the association has done their due diligence and accounted for the capital assessments properly.