PROBLEM: Help in The Gimp (no help came)

Until fairly recently I've been able to access the help files in The Gimp
(an open source, public domain image processing program) with no problems.
Recently, however, when I tried to look at Help the page came up in an HTML
editor (PageSpinner 5.0, to be exact). I could use PageSpinner's preview
feature to view the help (instead of its HTML code), but this is not very
satisfactory--nor the way Help had worked previously.

I checked Preferences in The Gimp and found that it was (apparently) trying
to view Help in a browser, but no browser was specified. Another choice was
the (built-in) Gimp Help Browser. I switched to that choice, but when I
tried to get Help I was told that the necessary plugin was missing (I went
to the Gimp plugins page but was unable to find that plugin).

Next I switched back to web browser and specified Safari. choosing Help
brought up Savari, but with a message saying that "Safari can¹t find the
file. No file exists at the address <path to Gimp help file>" (and doing
this also brought up a new instance of Safari, though Safari was already
running).

I have not even been able to get back to displaying Help in PageSpinner,
which at least let me see it. Furthermore, I can no longer get to the Gimp
website from The Gimp Online (one of the choices under Help).

Something has clearly gotten messed up, but what that might be is a mystery.
Has anyone else had the same experience (and found a solution)?

The Gimp 2.2.11 on a G5 Mac running OS X version 10.4.10.