Macintosh Fork Failure

Random failures on my macbook air today. Oh I see, fork failures. The default maxproc setting is ridiculously low (512).

Let's double that:

% sudo sysctl -w kern.maxproc=1024
kern.maxproc: 532 -> 1024
% sudo sysctl -w kern.maxprocperuid=1024
kern.maxprocperuid: 512 -> 1024

Now let's check the ulimits, now that only my shells are affected.

% ulimit -a
-t: cpu time (seconds)         unlimited
-f: file size (blocks)         unlimited
-d: data seg size (kbytes)     unlimited
-s: stack size (kbytes)        8192
-c: core file size (blocks)    0
-v: address space (kb)         unlimited
-l: locked-in-memory size (kb) unlimited
-u: processes                  266
-n: file descriptors           2560

% ulimit -a 512

Now, why am I still getting fork errors when opening a new terminal? What process has this 266 locked in?