When adding a new .xsd file (say MyPrivateDataSet.xsd) which has a code generated by xsd.exe (named MyPrivateDataSet.Designer.cs) to Windows Form project i get following strange behavior:

1. CustomTool property is not set to "MSDataSetGenerator"
2. After opening first time via "Open With..." option (set by default to DataSet editor, although Open option opens it as XML scheme editor) and pressing OK in the following dialog I do not see that the .cs file is attached. Moreover if i success to attach the file (usually as one under MyPribvateDataSet.cs) it is deleted on the first attempt to enter custom code. After this, the attempt to open the file in the Designer displays error that some constraint (_CONSTRAINT1) is invalid.

Please define what are rules for adding customly created .xsd with generated code as a dataset into VS2005 project.

Thank you.