Berkeley DB Family

I'm getting errors about "Too many open files" when trying to use Berkeley DB on Mac OS X 10.7.5.

The BerkeleyDB site mentions this, but it goes back to 2003 and refers to a file which doesn’t exist in OS X 10.7.5:

http://docs.oracle.com/cd/E17076_03/html/installation/build_unix_macosx.html

I tried ulimit, but it doesn't seem to have any affect:

$ sudo ulimit -n 1024 1024

Password:

$ ulimit -a

core file size          (blocks, -c) 0

data seg size           (kbytes, -d) unlimited

file size               (blocks, -f) unlimited

max locked memory       (kbytes, -l) unlimited

max memory size         (kbytes, -m) unlimited

open files                      (-n) 256

pipe size            (512 bytes, -p) 1

stack size              (kbytes, -s) 8192

cpu time               (seconds, -t) unlimited

max user processes              (-u) 709

virtual memory          (kbytes, -v) unlimited

Any suggestions?

Thanks,

James.