This might be a dumb question, but those sort of things always bite me so I figure I'll mention it anyhow:

Looking at your page, it looks like *possibly* the default font size on your IE 9 is different. It also looks like the browser window itself is larger. You may want to check that the settings in IE 9 are set to normal and you are testing the exact same window size. 

---

If all of that is set to normal I'm guessing it's differences in how ie 9 renders things. In addition, IE 9 is over 4 years old at this point. Designing any web based page, especially web forms for different rendering engines is tough, especially when the rendering engine has been replaced a few times. At the time Forms was released IE10 was the "modern browser" in the IE family. In fact, the Laserfiche Forms inbox, Form Designer, Process Modeler, Administrative pages, etc. only work with ie10 or above! (plus newer firefox/chrome builds)(http://www.laserfiche.com/support/webhelp/LaserficheForms/9.2/en-us/Forms/Default.htm#Administration/Installation.htm?Highlight=client workstation)

You'll also find that your cursors, text boxes & notification messages (i.e. the popups when you are missing a field or have wrong data used for javascript validation) will look different between browsers because they are controlled by the browser. HTML5 compliant browsers give you some control over this but IE9 doesn't implement all of the same HTML5 standards that newer browsers do.  And the validation messages are still independent from browser to browser.