John,

SET SNIP ON
>Good clients are satisfied; those who hammer you regardless are going to anyway, so you might as well be honorable.
SET SNIP OFF

IMHO, good clients aren't *always* satisfied -- they just understand, to a certain level, how difficult (read:impossible) it is to produce a bug-FREE product (no flames here, folks -- I know at times we need to do a better job finding and fixing bugs). I've had many excellent clients who are *very* tough when the chips are down, a deadline is near and a major module blows up. These same clients are savvy enough to know *when* and *how hard* to hammer the developer(s) when a bug is discovered.

I'd even go so far as to say "if a client hammers you regardless, they shouldn't be your client for long".

Personally, my answer to the base question of this thread is "whenever you can, always if possible". The large majority of clients are willing to accept "this update adds these features and fixes this list of minor 'gotchas' at the same time" without question. In situations where the discovery of a bug can cause internal issues at the client, I try to have a single "anomaly reporting" contact who can manage the FUD and calm the wolves.