In one of our share point site we have an browser enabled Infopath form.

On an event in a custom webpart --> Initialize the XmlFormView

In FormEvents_Loading event --> call a web service (to retrieve data) -->
populate the controls on the form --> Submit the infopath form using a data
connection to a document library on share point site

It works absolutely fine except when we get German characters like ä, ö, ü
or « etc.

These characters are within a string text which is bound to a Text Box /Rich
Text Box.

The text is populated in Text box/Rich text box without a problem but when
the form is submitted to Document Library, these characters are converted to
??

So next time when we open the form it shows question mark (??)

Could you please provide some inputs to resolve this? What happens when we
submit the form to document library.

Thanks,
Chinmaya.