specify field fill order

[buck2202]

I am attempting to use chromeIPass's "additional fields" functionality to control a drop-down box on a login page. My keepass database has the proper KPH entry, KeePassHttp is properly configured to return it, etc. My issue is that when the dropdown box selection changes, this particular web page automatically clears the username and password field. So, the flow seems to be

1. chromeIPass fills username/password
2. chromeIPass sets dropdown box
3. login page clears username/password

Asking chromeIPass to fill the fields again just repeats the process, as the string-field set operation seems to register a change on the webpage whether or not the dropdown value was already correct.

Is it possible to control the order in which chromeIPass fills fields? This issue could be avoided if I could configure it to fill the string field before the username/password.