I noticed that my site collection administrators weren't able to see their usage statistics. The issue was that the "Enable advanced usage analysis processing" checkbox was unchecked on the SSP's "Configure Advanced Usage Analysis Processing" screen. Here's what needs to be done to resolve this issue.
1. Open up SharePoint Central Administration
2. Click on the link to the SSP site home page.
3. Click on the link to "Usage Reporting" under the "Office SharePoint Usage Reporting" heading. This is _layouts/SpUsageConfig.aspx on the SSP site.
4. You will be on the "Configure Advanced Usage Analysis Processing" screen. Make sure that both checkboxes for "Enable advanced usage analysis processing" and "Enable Search Query Logging" are checked. Then press OK.
5. Now go to each Site Collection's Features (i.e. _layouts/ManageFeatures.aspx?Scope=Site from the site collection root).
6. If the Reports feature is activated then deactivate it.
7. Now click the Activate button for the Reporting feature.
8. As data is collected the site adminsitrators can use _layouts/SpUsageWeb.aspx on their site to see their site's statistics.
9. As data is collected the site collection administrators can use _layouts/SpUsageSite.aspx on their site collection root to see their entire site collection statistics.