pg_restore [archiver] file offset in dump file is too large

Posting here because it may be a 8.1 pre-release problem. I'll take
it to the admin list if it looks like it's not.

File dumped from 8.1beta3 using pg_dump -Fc on Linux box.
This dump restored successfully onto 8.1RC1 on Linux box.
File FTP'd to Windows box; attempt to restore onto 8.1RC1 fails with:

pg_restore [archiver] file offset in dump file is too large

This happens even wilth pg_restore -l <filename>

All instanced init'd with --locale=C

Both Linux and Windows 8.1RC1 instances give:

dtr=> \l
List of databases
Name | Owner | Encoding
-----------+----------+-----------
dtr | dtr | SQL_ASCII
postgres | postgres | SQL_ASCII
template0 | postgres | SQL_ASCII
template1 | postgres | SQL_ASCII
(4 rows)

(Source database was also SQL_ASCII.)

On the Linux box:

; Archive created at Mon Oct 31 20:00:01 2005
; dbname: dtr
; TOC Entries: 166
; Compression: -1
; Dump Version: 1.10-0
; Format: CUSTOM
; Integer: 4 bytes
; Offset: 8 bytes
; Dumped from database version: 8.1beta3
; Dumped by pg_dump version: 8.1beta3

-rw-r--r-- 1 postgres users 40874747876 Nov 1 05:27 dtr.dump

On Windows, the file size and md5sum -b result is identical.

Any suggestions on things to check or try?

-Kevin