[GENERAL] pg_restore - invalid file problem

[Ralph Smith]

In preparing to upgrade, (a long story), of our version 7.4 database  
cluster,
I'm trying pg_restore using the file from pg_dumpall, also version 7.4
into a virgin install of PostgreSQL 7.4 on Ubuntu.
Postmaster is up and running (c/o ps -ef)
The error I get:
pg_restore: [archiver] input file does not appear to be a valid archive

Where should I start looking for sources of the error?

Thank you!

Ralph
====================================================