таже проблемма... мы выкрутились - руками дамп правим, благо таких мест мало :)
но тоже очень хотелось бы узнать более правильное решение..

во... поискал повнимательнее и нашел.

Bug #787: Backup Files Output Constraints Before Functions

pgsql-bugs ( at ) postgresql ( dot ) org writes:
> Would it be possible for pg_dump to do the right thing here?

Not real soon :-(. It's possible that 7.4 pg_dump will be smart enough
to handle circular dependencies like this one. The current pg_dump
doesn't even know there is a problem, much less have a strategy for
coping.

I assume you can't simply create the try_it() function before the table
that uses it? (If you rewrote it as a plpgsql function, you probably
could do that, since the body of a PL function isn't checked when it's
defined. Perhaps this can serve as a workaround until pg_dump gets
smarter about dependencies.)

regards, tom lane