Descriptive Problem Summary:
When the "Show shout-box" Option in the Manage Account - Settings page is checked and saved, no shout-box will appear on a user's site.

Numbered Steps to Reproduce Problem:
1) Go to My Account > Manage Account.
2) Scroll down to User Page Settings.
3) Check the box next to "Show Shout-box".
4) Click save.
5) Go to My Account > View Site.
6) Observe that there is no shout-box present.

Expected Results: To have a shout-box visible.

Actual Results: No shout-box is visible.

Does the problem occur:
Every time? Or how often? Yes, every time.
In other user accounts? Untested.
On other computers? Untested.

When does the problem NOT occur? It would appear that since some members do have a shout-box, this only occurs for users wishing to add a shout-box. (Which, to answer the question, the problem doesn't appear to occur if you have already had a shout-box.)