out of memory in backup and restore

Hi,

i'm running pg 8.1.0 on a debian linux (64bit) box (dual xeon 8gb ram)
pg_dump creates an error when exporting a large table with blobs
(largest blob is 180mb)

error is:
pg_dump: ERROR:  out of memory
DETAIL:  Failed on request of size 1073741823.
pg_dump: SQL command to dump the contents of table "downloads" failed:
PQendcopy() failed.
pg_dump: Error message from server: ERROR:  out of memory
DETAIL:  Failed on request of size 1073741823.
pg_dump: The command was: COPY public.downloads ...  TO stdout;

if i try pg_dump with -d dump runs with all types (c,t,p), but i cant
restore (out of memory error or corrupt tar header at ...)

how can i backup (and restore) such a db?

kr
Thomas