In K2.net 2003, when developing a InfoPath ingegrated process, if you modify the InfoPath design (schema, view..., etc), you should sync the change back to K2 process.
Please follow the step:
Open the process in K2.net studio, right click the canvas -> Properties -> pay attention to "InfoPath Document Actions" dorpdown list, select "Refresh Document" command, wait for few seconds, a dialog will prompt you update successful.
Throuth this way, you can see newly added schema, view of InfoPath in K2.net Studio.
Remember: Each time you modify the InfoPath schema, you should repeat this action to make K2.net InfoPath integrated process's datafield sync with you InfoPath document.