The org.eclipse.help* plugins have had all of the tracing features removed for the Europa release. Why? Only this bug 197335 report will possibly tell.
They did leave the
.options file in the plugins so that your run configuration appears to support help tracing. It doesn't so don't waste your time trying.
What you can do is set a break point in
org.eclipse.help.HelpSystem.getContext(String). It will show you the help context id being used. Most problems are due to simple typos in your help *.xml file or in your view/editor/dialog call to