Can't drop / access / or create database

I'm trying to drop and re-create a database using postgres 7.1.3. When I
try to drop the database using postmaster, I get the following error:

postgres% dropdb surveyDB
pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.
connection to server was lost
dropdb: database removal failed

I then tried:

dropdb -i surveyDB

This seemed to go through, though I heard no disk activity.

Then, when I tried to recreate the database, I got:

postgres% createdb surveyDB
ERROR: CREATE DATABASE: database "surveyDB" already exists
createdb: database creation failed

When I try to create another database:

postgres% createdb BS
pqReadData() -- backend closed the channel unexpectedly.
This probably means the backend terminated abnormally
before or while processing the request.
connection to server was lost
createdb: database creation failed

This isn't the first time this has happened to me. Does anyone have any
suggestions on how I can get out of this mess? The database is no longer
useable.

Thx,
Peter