array_to_string(anyarray, text) that was working in 8.1 is not working in 8.3

Help!
I'm trying to use array_to_string on the pg_stats column
histogram_bounds...

test83=# select array_to_string(histogram_bounds::anyarray, '-') from
pg_stats where attname = 'id' and tablename = 'widgets';
ERROR: argument declared "anyarray" is not an array but type anyarray


In 8.1, it worked fine...
test81=# select array_to_string(histogram_bounds::anyarray, '-') from
pg_stats where attname = 'id' and tablename = 'widgets';
array_to_string
---------------------------------------------------------------------------------------------------------------------

140554732-572177261-753193757-830984044-942651560-1085142858-1287313768-1418796327-1623947492-1865024250-3199068162

Any help would be appreciated, whether a known fix to this, or any
workaround you can think of.

Thanks!
Corey Horton