Unfortunately Microsoft hasn't given any significant resolution in the article.
Based on my experience, this is common error. However, it is inevitable that InfoPath forms cannot have view state like ASP.NET pages. Hence, it will not persist the previous state of the object and as a result we will receive error like this - "There has been an error while processing the form."
And no further information. Everybody has to scratch their head.
Here are few scenarios, to trouble shoot the error
1. You delete rows from InfoPath form which will delete respective rows in database and as per user requirement again you have come back to the same form. - Here we will get error, suppose if you are not binding data from database (I mean we should refresh data again from database to get latest data). So in your code write a logic to refresh data.
2. Sometimes when you refresh form and click on few controls which has to get data from database. Because InfoPath is very light weight and will persist the state of the objet.
Hope this helps for few scenarios.....