When you go to yoursite.com/manager/ to log in what do you receive for error?
TinymceWrapper: Complete back/frontend content solution.
Harden your MODX site by
passwording your three main folders:
core, manager, connectors and renaming your
assets (thank me later!)
5 ways to sniff / hack your own sites; even with renamed/hidden folders, burst them all up, to see how secure you are not.
discuss.answer
I have just re-installed MODx following the same steps as described in the first post and it works.
Although I have tried installing it twice before posting the problem, I must have been configuring the passwords wrong.
Conclusion
False alarm... the advanced installation works fine.