Make sure you have Formidable styling enabled in both the Formidable -> Settings and the individual form settings.
Compare the form preview page with the form in your theme. Any differences are caused by your theme.
Several themes are adding extra space between field labels, the required symbol, and fields. WordPress adds HTML (<p> and <br/>) automatically, and some themes send it through this WP filter multiple times which adds paragraphs and line breaks inside the form. In many of these themes, you can fix this by replacing [formidable id=x] with
[formidable id=x minimize=1]. This will minimize the form HTML so there is nowhere for your theme/other plugins to add the extra <p> and <br/> tags.
I LOVE that you can use forms to create content. Awesome, awesome work! Formidable Pro has totally changed the way I think about how to use WordPress. For the first time ever I can see being able to use WordPress as database.
Chris Howard (341 design & Headway Themes)
After spending countless hours customizing forms in WordPress for our clients, Formidable Pro is a breath of fresh air. It merges high level customization with extreme ease of use. I would recommend Formidable Pro to anyone looking to create forms in WordPress!