Scott,
MyEclipse 7.5 is something like 8 releases after MyEclipse 6.0.1, the 6.x series was based on Eclipse 3.3, the 7.x series is based on Eclipse 3.4 — we build on a huge portion of Eclipse and all sub projects, so no, it’s not backward compatible. The amount of API and code changes between each Eclipse release is significant and breaks quite a bit of our product, that’s why we have to tie it against major release trains.