When this happens the first thing I check is the form submit data connection. You want to have a constant field name used for the form title, and not a form title that will change with every submit. If the form title changes with every submit, then you'll get many forms created.
So, for example:
1. add a field called FormName
2. set up a form load rule that only executes when FormName is blank, and set it equal to whatever form name you'd like.
3. set the data connection to submit using this FormName and check the option to overwrite.
This way you're only setting the FormName once (on load when it is first created), and not re-setting it with every submit.
Good luck!