See if the following instructions help:
Add the uploaded form to the existing site content types:
1. Navigate in IE to your MOSS server: http://machinename
2. Navigate to your Form Libary.
3. Choose Form Libary Settings from the Settings drop-down.
4. Click Add from existing site content types.
5. Select Microsoft Office InfoPath from the Select Site Content Types From drop-down.
6. Select your form template in the Available Site Content Types list and add it to the Content Types To Add list.
7. Click OK.
To set the new button options,
1. Navigate in IE to your MOSS server: http://machinename
2. Navigate to your Form Libary.
3. Choose Form Libary Settings from the Settings drop-down.
4. Click Change new button order and default content type.
5. Clear the Visible check box for Form.
6. Click OK.