While working on an InfoPath form for Forms Servers today I encountered this error when running the form in Forms Services: Unexpected end of file while parsing Name has occurred. Line 1, position 569. It really confused me considering I was developing my form in Forms Services compatibility mode and the forms worked perfectly in the preview mode of InfoPath. After doing some Googling, I discovered this blog: http://sharepointben/s.msdn.com/infopath/archive/2006/11/22/workflow-user-experience-in-infopath.aspx
Apparently this is a known issue in Forms Services. If you have a secondary data source in your form that is not be referenced anywhere within the form, this error will occur. To fix it you must either figure out which data source you aren’t referencing anymore or create some field that references that data source (you can hide the field if you don’t need it).
As soon as I deleted the unused data source in my form, it started working perfectly again.