b. Earl Britt reminds me that there is a 6.0.2 upgrade to Adobe Illustrator (it's been around since January). However, you need 6.0.1 to run it. If you only have 6.0, Adobe will mail you a 6.0.1 CD for "free" ($9.9.5 for shipping). You need the 6.0.2 update for compatibility with ATM Deluxe. Of course, you can also decide to upgrade to Illustrator 7.0, coming next month.
Update: Adobe disagrees with Earl, writing: "Illustrator 6.0 is compatible with ATM Deluxe 4.0. Nothing was added to Illustrator 6.0.1 nor 6.0.2 which would add greater compatibility."