I was experiencing the same problem as Goldblatt when trying to run tomcat in debug mode. Also, subclipse was not working at all: javahl doesn’t work on os x 10.6 and switching to svnkit didn’t work).
I tried to re-install myeclipse 7.5 using the self-contained installer, but that hung in the middle of the process. I then tried installing using the update site over 3.4.2 classic and it complained about a dependency with eclipse.ui.ide (which was installed).
I finally tried installing only the “MyEclipse Enterprise Workbench” and “MyEclipse Tomcat Support” features, as these give me everything I need. This installed fine. After this, I installed the latest version of subclipse from its own update site.
Now everything is working fine. I can run Tomcat in debug mode and use svn without problems. I have the following installed:
Eclipse SDK 3.4.2.M20090211-1700
MyEclipse Enterprise Workbench 7.5.0.zmyeclipse75020090612
MyEclipse Tomcat Support 7.5.0.zmyeclipse75020090612
Subclipse 1.6.5
Subversion Client Adapter 1.6.4.1
Subversion Revision Graph 1.0.7
SVNKit Client Adapter 1.6.4
SVNKit Library 1.3.0.5847