updating a secondary datasource to a Sharepoint list via infopath form rules

Using SharePoint 2010 and InfoPath 2010 I created a form that prior to submission it gets an integer value from a separate SharePoint list via a secondary datasource.  Just before the rule that submits the form to a document folder via the main datasource I increment the integer value and try to write it back to the secondary datasource I got it from.  I know that I have the correct value.  That is, it is reading from the data source the correct integer information and it is incrementing it in the form but when it writes the value back to the same column in the same secondary datasource it doesn't give any indication that it didn't work.  But when I look at the list of the secondary data source I see that the integer value is not updated.