Freeze when trying to run a pg_dump backup file as SQL query

I've reliably reproduced the freezing bug I mentioned before (in the
suggestion to save query text). pgAdmin freezes when I try to run a
backup file created by pg_dump from an SQL query window. The file
contents look like this:

COPY much_data (some_data) FROM stdin;
BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH
BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH
BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH
BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH
BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH
\.

When I run that the output window shows:

ERROR: syntax error at or near "BLAH"
LINE 2: BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/BLAH/...

That's fine (well, it would be nice if pgAdmin supported restoring such
files, but that's another story) - but then it freezes. It doesn't
happen with 5 lines as above, but if I have 100 lines of data that's
enough to make it freeze for a few seconds. With a real back-up file of
1 MB or more it probably won't come back any time soon and has to be
killed. (It doesn't need to be real data - just copy/paste the 5 BLAH
lines above 20 times to reproduce the problem.)

I'm running pgAdmin 1.14.3 running on Windows 7 (x64), PostgreSQL 9.1.3

Regards,

Evan