Formerly I was using the SvnKit (pure-Java) libraries. SvnKit "felt" slow to me, compared to my command line SVN client, so this time I tried to get the JavaHL (JNI) libraries working.
For the record I'm using Ubuntu (jaunty) with Eclipse 3.4 (Ganymede). This version of Ubuntu comes with Subversion 1.5, so I need to install Subclipse 1.4. See:
I installed everything through the Eclipse update manager (minus SvnKit), but JavaHL didn't show up under Preferences -> Team -> SVN. The error message was. JavaHL (JNI) not available.
I had installed Eclipse manually (not through apt-get), so the solution was to install the JavaHL libraries:
apt-get install libsvn-java
and add the following line to my eclipse.ini (usually in the top level eclipse directory):
Restart Eclipse, and you should be good to go!