Resource file: Is OK (good idea) to mix different versions of Resource files (.resx) in a project?

Our projects are VB.NET (I assume that question should be same for C#) and support localization.

We notic that when we move from .NET framework 2.0 to 3.5.

If we open a form in design mode and save, the resource file version will change from version 1.3  to 2.0.

However, if we does not open a form in design mode, the resource file may still in version 1.3.

Specially, the older localized resoure file (form1.fr.resx) may still keep as version 1.3

<resheader name="version">
    <value>1.3</value>
  </resheader>
<resheader name="reader"><value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value></resheader><resheader name="writer"><value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value></resheader>

<resheader name="version"><value>2.0</value></resheader><resheader name="reader"><value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value></resheader><resheader name="writer"><value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value></resheader>

Is it OK or good idea to keep mix versions of resoure files in projects?

Or it is best practice to update all resource files to the same version 2.0?

thx! 

JaneC