Problem with colour on panoramic photo

I have created some panorama photos using the Photocreate option in PS Elements. However, a few of them ended up with colours that do not fade smoothly into each other. eg.

http://community.webshots.com/photo/73198097/75008984JQyDnC

Can anuone help to suggest techniques/processes to smooth out the colour transition, please? Thanks.

I'd just use the burn and dodge tools to lighten or darken areas of the sky and try to get it to match up better or make a more smooth transition. Don't know if Elements includes the burn and dodge tools though...