VC++.NET bug or missing setting inside the project?

[Severino]

Hi all,

we have developed a .NET component for use inside Windows Forms: this
component has been written using VC++.NET (2003) and is working perfectly
when inserted inside VC#.NET or VB.NET projects; its generated assembly is
inside MyAssembly.dll
When used inside a VC++.NET project it appears correctly over forms at
design time but when trying to compile the project we get the following
error:

********************
error: Invalid ResX input.
error: Specific exception: SerializationException Message: Invalid ResX
input. ---> SerializationException: Cannot find the assembly MyAssembly,
Version=1.0.1567.39527, Culture=neutral, PublicKeyToken=null.
2 error(s).
TestCppDotNet : error PRJ0002 : error result returned from 'resgen.exe'.
********************

After some trouble, we have identified the problem inside the .resx file: we
have two properties that store their value into a base64 value as in the
example below, using the "application/x-microsoft.net.object.binary.base64"
mimetype:

<data name="MyCtrl1.BoxedPictureTexture"
mimetype="application/x-microsoft.net.object.binary.base64">
<value>
VALUE CONTENTS....
</value>
</data>
<data name="MyCtrl1.Texture"
mimetype="application/x-microsoft.net.object.binary.base64">
<value>
VALUE CONTENTS....
</value>
</data>

If we remove these two properties, the problem disappears: not that the same
values are stored and managed correctly inside the .resx file of a C#
project: are we missing some namespace declaration?
Why VC++.NET fails to compile this resx file?
Is this a bug?
Any solution?

Thanks in advance and Kind Regards

Severino