XML tags all upcase

I experience a strange behavior of the MSXML3 parser: My code uses the MSXML3 component (CLSID_XMLDocument, through the IXMLDocument, IXMLElement, IXMLElementCollection interfaces) to parse XML files.

The strange thing is, that all XML tags are obviously parsed in uppercase letters. It furthermore all seems as if the XMLDocument is ignoring the case, because I can easily find elements by names passed in lower/mixed case. Also, the XML parser does not complain when the case of the opening and closing XML tags does not match.

Did anyone else ever experienced something like this?
Do you have an idea how I can change this behavior?

Thank you!