- Log in as an admin
- Follow the admin link in the administration block
- Go into variables
- Find the term messaging (Use ctrl+f in the browser for extra speed)
- Set to yes.
Hope that helps
It has occurred to me that it would be nice it when making a solution post like this the it could be flagged as an answer to an FAQ somehow. Even just a link somewhere in this page to make it easier for me to copy / paste the response to the docs project.
When you are in the variables page click on the permissions link at the top to jump you down to the correct section.
The only thing I can think of is you have missed it, it's not an english install or you are not running 1.5!
There isn't a permissions link at the top!
Regarding the 3 possibilities you listed, I've checked a number of times and am sure that I have not missed it (I also did a control+f search), it is an english install, and the version of Moodle I am using is 1.5 development. Perhaps 1.5 development doesn't allow messaging blocks?
Can't remember off the top of my head. Somebody else would have to cover that one.
I know this sounds like a MS cop out but have you considered upgrading anyway?