Hi Patrick,
Thanks for the quick reply.
I have tried modifying the XML using notepad (we use SharePoint 2003, WSS 3.0) but the href attribute only references the template location - I haven't moved the xsn template, just the files created from them.
I don't think I have explained correctly. The InfoPath forms are completed daily, at the end of every month a SQL DTS is run to move them into a folder for that month - i.e. the forms currently being completed will shortly be moved to a "June 2011" folder, within the same form library.
I no longer want the forms in separate folders, so tried to move them out and delete the folders. Now when I try to save updates to a form created in May (that was saved in the May 2011 folder until I moved it out) I get an error to say the folder is no longer available.
My submit data connection just points to the form library, not a specific folder.