I have a couple of nice flights picked out from itasoftware.com: pdx-mrs, cdg-pdx, and las-mrs roundtrip for my friends. I haven't been able to bring them up with the same prices when I go to the airline website, Air France. Any advice?

See if you can get it on Orbitz.com.

It will cost you a booking fee, but calling the airline and/or travel agent will get you the fare. Most airline sites are limited as to which fare codes they will price. A phone agent or TA can pull up the fare codes that you found on ITA.

grrrr...the airfares are so high I keep distracting myself with searching one more site or one more route and then it looks good but then the connection time is too short or the layover is too long and it goes on and on and on.....
Thanks for the advice, both of you. I think I will be using both of those options.

o.k., got it! Went through United telephone reservations, had a wonderful agent (David) who worked with me for probably half and hour, and now we have tickets to meet our friends in Chicago, fly to CDG, train to Marseille. Our friends are departing out of Toulouse, and we will fly out of CDG. Ta-daa! Approx. $806 per person. More than I expected to spend but I'm satisfied considering current airfare, our schedule, and including the train segment we wanted just for the experience.
thanks again rk and aaff. you were right on.