First you need to cvsup the ports tree then do this as root:
# portupgrade -aRr
This should fix everything right up, then you just need to add a cvsup script into your cron and another weekly one for portupgrade.
For future reference 99% of port problems are due to the fact your tree is out of date.
Cheers and check this out if you dont know how to cvsup.
http://www.freebsdforums.org/forums/...=&postid=57384