Html Export of RadRichTextBox exports all spans with empty font-style when the following export settings are used:

HtmlFormatProvider provider = new HtmlFormatProvider();
HtmlExportSettings exportSettings = new HtmlExportSettings { DocumentExportLevel = DocumentExportLevel.Fragment, StylesExportMode = StylesExportMode.Inline };
provider.ExportSettings = exportSettings;
string result = provider.Export(this.radRichTextBox1.Document);