ASP.Net Profile

Hi,
 I am  using asp.net membership and profile. All my asp pages inherit from a base page. I am trying to read the user profile in base  page class using ProfileCommon class but it throws exception that it can't find the properties e.g FirstName which is defined in the user profile.
 Is  there any reason why you can't read a user profile in basepage?
 
thanks
 
Rajesh 
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