archive is compressed - any data will not be available

Hi All,

I'm hoping that soemone can explain this error message to me and give me an
idea of how to proceed.

I was given a set of 3 dump files (in a tar.gz archive) generated by a 7.1
DB that I'm trying to import into another 7.1 DB. 2 of the files (the
smaller ones) restore no problems, but one gives the above mentioned
message. As far as I know all 3 dumps were supposed to have been performed
using the same options (this might not be the case, but I can't tell for
now).

Following are a couple examples of the output:

[postgres@mst0001 1210]$ pg_restore --list orig_main.dump > orig.list
Archiver: WARNING - archive is compressed - any data will not be available
[postgres@mst0001 1210]$ pg_restore  orig_main.dump > orig.dump
Archiver: WARNING - archive is compressed - any data will not be available

Archiver: ******** WARNING ********
        Data restoration may fail since any defined triggers
        can not be disabled (no superuser username specified).
        This is only a problem for restoration into a database
        with triggers already defined.

Archiver: Unable to restore data from a compressed archive

The list is generated fine, and restore proceeds until the first data load
before failing.

pg_restore --help doesn't give me any clues as to other options that I
should try.

Any suggestions?

Thanks
Iain