We have a few portlets (struts/jsr168) that add rows to a database when a submit button is clicked. We recently migrated our portal from 5.1 to 6.1, and now users are reporting duplicate rows being written to the database. I am able to reproduce the problem by repeatedly clicking the submit button on one of the portlets, so I suspect that some users are absent-mindedly double-clicking the button. I tried the same thing in the old 5.1 environment, and am unable to reproduce this. I am just wondering what might be different between 5.1 and 6.1 that would cause this? Have you seen this problem, or do you have any insight as to what might be different now?