Did you disable the submit button when it is clicked?   It seems like the user is able to click it multiple times.

I bumped into this a short while ago.

The cause of my problem had to do with placement of a submit button at the bottom of an InfoPath form I developed. InfoPath has a submit button in a toolbar that is present by default -- so there are two submit buttons present. The problem was that the form was actually being submitted twice -- hence the duplicate data with distinct process ID's.

I also saw similar behavior when InfoPath presented a prompt ("Are you sure you want to submit Form 1?"). When that prompt was displayed, the form was already submitted. Answering the prompt with a "Yes" submitted the form a second time.

YMMV, but a combination of using logic to control the multiple submit buttons plus disabling the prompt allowed me to erase the problem. I"m hoping these descriptions gave you some ideas on how to attack it.

Hi peter, thanks for  your reply. you are right it was in the submit button being click multiple time and ill create instance in K2 in accordance to the times the user click the submit button "When the page is still posting back. however you can't disable the button while the page is posting back so what I did is a created a modal form that will disable the page until the page has completed its reload or post back and then when the user clicks again the submit button I cross check the Request No. if its existing in the database an if it does exist I generate a new request No. for that instance. Thanks a lot guys...

Hi Tony, thanks for  your reply, i'm using ASP.net forms, it was in the submit button being click multiple time and ill create instance in K2 in accordance to the times the user click the submit button "When the page is still posting back. however you can't disable the button while the page is posting back so what I did is a created a modal form that will disable the page until the page has completed its reload or post back and then when the user clicks again the submit button I cross check the Request No. if its existing in the database an if it does exist I generate a new request No. for that instance. Thanks a lot guys...