... or why does your tool introduce bugs in my code and doesn't warn me?
When migrating an ASP.NET 1.1 project to 2.0, using the VS 2005 (SP1) conversion wizard and the Web Application Project conversion tool (included in service pack 1), the AutoEventWireup @page attribute is set to "True" for all pages, even when you previously had set it to "False".
This potentially breaks your application, when you have eventhandlers for init/load/prerender bound manually in places where the conversion tool doesn't change them, e.g. in the constructor of a common basepage. This will cause the events to be handled twice, with unexpected results.
The problem is not that the default is changed from 1.1 to 2.0, but that by modifying my code the tool introduces new (interesting) bugs. And all this without a big neon-sign, which warns for the changes being made and the potential problems it introduces.