pg_dump(all) fails with "failed sanity chec, type with oid ..."

pg_dump/pg_dumpall fail with the following messages (verbose output
selected):

...
--  dumping out user-defined procedural languages
--  dumping out user-defined functions
failed sanity check, type with oid 59770787 was not found

OS: Linux kernel 2.2.16
PostgreSQL v. 7.0.3

I've seen similar posts and suggested resolutions to the problems (which
I haven't been able to use), and I think this is a bug that's been put
on a TODO list.

So, two questions:

1) Is a bugfix for pg_dump/pg_dumpall available, perhaps in the 7.1
version?
2) If the bugfix is available in 7.1, can I safely migrate data from
7.0.3 to 7.1, if i use the COPY command to export and import tables.

Thanx.