We are getting intermittent errors when out users perform postback events from within our infopath 2007 forms hoseted within sharepoint 2010...
"The Canary data has been tampered with for form "
In the event log this is also logged as "The security validation for this form is invalid"
It does not always happen (it usually doesn't). A user can get this issue and then open a new form, fill it in in the same way and it goes through fine.
I have seen other similar posts which blame the issue on either an out or date core.js file, or else an issue in Microsoft.Office.InfoPath.Server.dll introduced in SP1. However, reading these posts I get the impression that these issues are not intermittent so I am not sure that mine is due to the same thing. Also, I am worried that replacing the DLL or the core file will intoroduce other issues.
I have been unable to reproduce the issue in our development or test environments so these solutions would be hard to test without doing them in live.
Does anyone have any ideas of how I can fixs this issue,
Kind Regards,
Dave Dixson.