  Let R be a regular local ring of dimension d, I an ideal of R, and M a
finitely generated R-module of dimension n. We prove that the set of associated
primes of Ext^i_R(R/I,H^j_I(M)) is finite for all i and j in the following
cases: (1) dim M\le 3; (2) dim R\le 4; (3) dim M/IM \le 2 and M satisfies
Serre's condition S_{n-3}; (4) dim M/IM\le 3, R is unramified, and M is
faithful and satisfies S_{n-3}.
  We also prove that if dim R/I\ge 2 and the punctured spectrum of R/I is
disconnected then H^{d-1}_I(R) is not I-cofinite. This generalizes a result due
to Huneke and Koh.
