So I have tried this again – JRuby on Rails in Eclipse IDE with WebTools Platform and RadRails.
Since RadRails 0.9.1 which has fixed compatibility issues with Eclipse 3.3 was out in November, I have upgraded Eclipse to 3.3.1 with WebTools Platform 2.0.1. I have also upgraded Tomcat to 6.0 as WTP 2.0 supports it.
ActiveRecord-JDBC 0.7 and GoldSpike 1.4 are just out, too. Basically I have upgraded everything and they have worked well together. I am going to upgrade or maybe re-write a few of my old rails apps in this development environment. How exciting!