Compilation error when inheriting a partial class page

[dinesh]

I am using ASP.Net 2.0 ,i've inherited a page in another page.
During compilaton I get the error saying
" the "base class" could not be found"
But when I rebuild the application the error goes. This behaviour is
very random.
Sample code in the code behind files

public partial class baseClassName : System.Web.UI.Page
{
//Code
}

Now when I inherit this page in another page

public partial class derivedClassName : baseClassName
{
//Code
}

I've also tried putting the base class in a namespace and then
including it in the derived class
but then it says the namespace could not be found.

Is it not right to derive a page in asp.net2.0 ,or it is a problem
because of partial classes?