Teens less interested in business careers?

An organization called Junior Achievement, whose goal is to "educate students about workplace readiness," has been polling teens for several years about their ideal job. This year's poll, publicized with the headline "NATIONAL POLL: TEENS' RANKING OF CAREER AS "BUSINESS PERSON" FALLS FROM FIRST TO FIFTH PLACE," showed some major changes from previous years:
"Business person" is down, and "Science/Engineering" and "Doctor" are way up as desired careers. Looks like the economic upheaval has made a huge impact on teens, right?

Not so fast. There's some fine print at the bottom that's important to read:

The 2009 Junior Achievement Kids and Careers Poll was conducted by Opinion Research the week of January 12, 2009, and has a margin of error of plus or minus 3.6 percent. In previous years, the survey's methodology differed, and was conducted using an online survey tool.

I can't find details on their 2007 and 2008 careers polls, but they had many other polls conducted by Harris Interactive, an organization which asks volunteers to agree to be emailed about polls, and then selects a random sample from that pool. (Harris Interactive offers points for agreeing to be surveyed, which you can save towards prizes.) The sample is not remotely random, and the methodology is entirely different -- the poll is online, as opposed to by telephone. Drawing any conclusion by comparing these two older polls with the new random-sample based poll is impossible, because the differences in sample selection and methodology are just too large.