Postgres Crash

Howdy,

Environment:

Solaris 10
Postgres 8.3.12

Postgres crashed and left 26 postmaster processes active in it's wake. Killed the children and re-started postgres successfully. Messages from the log:

Dec 10 11:52:15 udrv postgres[771]: [ID 748848 local0.info] [6-1] host=,user=,db= LOG: setsockopt(TCP_NODELAY) failed: Invalid argument
Dec 10 11:52:20 udrv postgres[2183]: [ID 748848 local0.error] [1-1] host=,user=,db= FATAL: pre-existing shared memory block (key 5432001, ID 0) is still in use
Dec 10 11:52:20 udrv postgres[2183]: [ID 748848 local0.error] [1-2] host=,user=,db= HINT: If you're sure there are no old server processes still running, remove the shared memory block with the
Dec 10 11:52:20 udrv postgres[2183]: [ID 748848 local0.error] [1-3] command "ipcclean", "ipcrm", or just delete the file "postmaster.pid".

With the 'FATAL' and 'HINT' lines repeating.

Any ideas what occurred here?

Thanks,

Sam