Why does file open as form?

[Brett Romero]

I'm using VS 2K5. I break my forms into three files plus the RESX. I
usually have:
frmForm1.cs
frmForm1.Designer.cs
frmForm1.Logic.cs
ForForm1.resx

This allows me to double click the first file to get a designer view
and code view on the others w/o right clicking. It's also good
seperation of the auto generated wincode. I do this by editing the
csproj file:

<Compile Include="frmForm1.Logic.cs">
<DependentUpon>frmForm1.cs</DependentUpon>
</Compile>

On one project, this isn't working. The frmForm1.Logic.cs file always
opens in design view. That is supposed to only happen if
<SubType>Form</SubType>
is included in the <compile/> node. The file only contains this code:

namespace myspace
{
partial class frmForm1
{

}
}

Any ideas why this keeps happening?

Thanks,
Brett