Custom Role Provider Doesn't Work

Hi All.
I have a custom role provider and I'm trying to get the IsUserInRole() method to
get called when a user of a certain role tries to access a restricted page.
However, the method is never called.
<~location path="SomeFolderPath">
  <~system.web>
    <~authorization>
      <~deny roles="RestrictedUser" />
    <~/authorization>
  <~/system.web>
<~/location>
<~roleManager defaultProvider="MyRoleProvider" enabled="true">
  <~providers>
    <~clear />
    <~add applicationName="MyRoleProvider" name="MyRoleProvider" type="Test.MyRoleProvider" />
  <~/providers>
<~/roleManager>
namespace Test
{
  public class MyRoleProvid ...