shmget fails on OS X with proper settings

Hi to the list, its my first post.

I was previous running postgres 8.2.1 on my OS X 10.4.9 laptop with no problems.
After I sent it to apple care, I found that I can no longer start the
postmaster daemon.   When I try, I receive the standard shmget failed
error message:

FATAL:  could not create shared memory segment: Cannot allocate memory
DETAIL:  Failed system call was shmget(key=5432001, size=4112384, 03600).
HINT:  This error usually means that PostgreSQL's request for a shared
memory segment exceeded available memory or swap space. To reduce the
request size (currently 4112384 bytes), reduce PostgreSQL's
shared_buffers parameter (currently 300) and/or its max_connections
parameter (currently 30).

I get this error with either the settings recommended on the kernel
resources page:

kern.sysv.shmmax=4194304
kern.sysv.shmmin=1
kern.sysv.shmmni=32
kern.sysv.shmseg=8
kern.sysv.shmall=1024

And I also get it when i set kern.sysv.shmmax=12582912

After making all these changed rebooting doesn't fix anything.

Has anyone ran into this problem, or has any idea as to why this would
start to fail so suddenly?

Thanks,
Chris