I'd do a repair installation. And I'd first save out all the modified
files to another location before doing the repair.

Maybe SP2 is the answer - just not brave enough to try it yet.

If you had some customized web parts, make sure those web part are not
hanging the system. I had a couple instances where I had "bad" web parts
that hang the system.

And to assist in finding that out, look at the Dashboard Status tool,
which you can load on your management dashboard and it will list all the
personal dashboards, the owners, the last time they were modified and
which web part was the most recent one modified. This can help greatly
in troubleshooting if personal dashboards might have had an effect.

www.microsoft.com/.../default.asp

I'll have a look, could you shed any light on what would make a
webpart "bad"?

Anything that will timeout and bring the system down. For instance, if
you are running an web part with content link to an ASP page located on
the Sharepoint server  and that the ASP code hangs.

It happens to me with the content source administration web part from
the resource kit.

You would have to be brave. I put it on our test server  and it "ate" four
out of the five dashboards I had!! It just came up saying you have no
content on this dashboard add some. Its going no where near my live server.

That's a known problem  with SPS SP2A - Q813101

Do you have a link for that? It doesn't up via Technet.