The Reveal Page feature will only work when a user clicks on your App Icon, or is visiting the direct link to your Page Tab, like below:
www.facebook.com/smeconsulting/app_166882976745573
With the update to Timelines for Pages that Facebook finalized in April, the Page Tab can no longer be set as the default location a visitor goes to when they just visit your page.
Hope that explains, but if not, or the page I linked to above isn't your Reveal Page for the Page Tab, just let us know.
Thanks,
Alex