Compiler Error Message: ASPNET: Make sure that the class defined in this code file matches the 'inherits' attribute, and that it extends the correct base class (e.g. Page or UserControl).

I get this error RANDOMONLY.  The page works fine 50% of the time and the other 50% of the time I get this error:
Server Error in '/Navigation' Application. -------------------------------------------------------------------------------- Compilation Error Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. Compiler Error Message: ASPNET: Make sure that the class defined in this code file matches the 'inherits' attribute, and that it extends the correct base class (e.g. Page or UserControl). Source Error: Line 1: Line 2: Partial Class Top_Default Line 3: Inherits System.Web.UI.Page Line 4: Source File: D:\Domain\ssite\wwwroot\navigation\Default.aspx.vb Line: 2 This page is very, very simple.
Heres the .aspx page
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