Are you publishing the template straight to a form library or as a content type ?
If you publish a form as a content type, your newly added fields are not implicitly added to the view(s) of the libraries where you have "attached" your content type.
You simplly have to go and edit the view for your libraries (you can do this via list settings or just from the drop down list you can find in the upper right corner) and enable the check box that represents your newly added field.
HTH
Ciao