Maybe you can try the below link, Ted has given a wounderful moive to
work with workflow.

download.microsoft.com/.../a61dd5df-f52c-42d5-a95c-
7a7fb7a6a466/SpdWorkflow.wmv

I'd actually watched that before starting  - I think its because I'm
using different accounts for each service in MOSS - i.e. the timer
service is using the central admin account but I'm not sure this has the
right permissions to the content  db's and that may be my problem

Now that's really bizarre

I've rebooted the server and the workflow  is running just how you would
think

What I don't understand is why a server reboot is necessary to get a
workflow working !

I had tried an iisreset so I think I'll just have to replicate what I
did (i.e. create  a new site  / doc lib etc) and see what happens

So, what i do next is create  a new content  type (myType2) based on an
unknown content type  - even though the columns in this unknown content
type still derive from the document  and item  content types bizarrely
this works

I can delete the document content type from the list and the myType2
content is fully functional

Still cant explain why you cant hide content types if another visible
content type derives from them

Well, if anyones interested, I've nailed this down further and, on my
lab, can replicate it time and again

Create a different content  type (say, myContentType)

Add it to the doc library

Delete the document  content type  OR make myContentType the default OR
hide the Document content type

When you create  a new document from the myContentType by clicking on New
then the associated workflow  will hang at Starting

If you expose the Document content type and make it the default, it all
works again - i.e. clicking new works or even selecting a different
content type works and the workflow will, errr, flow

What I don't understand is why it should hang on "Starting" when the
default document content type is no longer the default

If anyone has any ideas  I'd be glad to hear them.