I didn't discovery the reason, but I tried a workaround and it worked.
So, you need to delete the registry key:
HKEY_CURRENT_USER\Software\Microsoft\VisualStudio\8.0
Additionally delete the folowing folder:
C:\Documents and Settings\”User”\Application Data\Microsoft\VisualStudio\8.0
> Some times my Visual Studio 2005 doesn't show me the migration wizard when I
> open a VS 2003 solution.
> Someone knows what's happening ?