pg_dumpall and pg_restore issues

Hi,

I'm having problems using pg_dumpall and pg_restore together.
Basically I can't get pg_restore to recognise the dump as a valid archive.

Example:
Create a dump like this pg_dumpall -U postgres -Fc -Z 9  > /tmp/dump
Then try to restore it
$
pg_restore -U postgres -Fc /tmp/dump
pg_restore: [archiver] did not find magic string in file header

or

$pg_restore -U postgres  /tmp/dump
pg_restore: [archiver] input file does not appear to be a valid archive

The dump file is strange too, it starts out as a standard SQL dump like
pg_dump produces, then shifts to binary, Iassume thats the compressed data.
The same pattern contnues throughout the file, straight SQL text then big
chunks of binary data.

Version:
$pg_dumpall --version
pg_dumpall (PostgreSQL) 7.2.1

Does anyone have any ideas?
Thanks,
Darren McClelland