pg_ctl reload - is it safe?

Env: Postgres 7.3.4 on Unix

I have a script to create a new database user and update pg_hba.conf.
I was wondering whether I need to restart server, or simply run pg_ctl
reload.
The question is what happens to all active clients when all backends get the
signal.

I ran such client process which was very busy querying and updating
database.
At the same time I kept executing "pg_ctl reload". Soon after client
reported
database error.

Here's the excerpt from the database log:
... ...
2003-10-10 22:33:12 LOG: Received SIGHUP, reloading configuration files
<25 successful SIGHUPs, about 2 seconds apart from each other>
... ...
2003-10-10 22:37:05 ERROR: cannot read block 0 of s_noteimportlinks:
Interrupted system call
...

From the client log I see that problem occured while trying to SELECT
nextval from
sequence s_noteimportlinks

We are going to pass this script to the customers and we have to know what
to recommend:
reload or shut down/restart. I hope they won't do reload 25 times... but
they may have
25 or more active client processes at any time.

Thanks in advance,
Mike.