trouble using ivy-svn in eclipse

I am trying to use IVY with Ivy-svn and IvyDE, but the two don't seem to work together.
I have configured everything to work when building from the command line, and building works just as well inside eclipse, but when I try to add IvyDE Managed Dependencies to the project, it gives me this error about the IvySettings file being broken.

> Problem occurred while using file:/C:/ivy/settings/ivysettings.xml to configure Ivy.
> Please set your ivy settings url properly in the preference or in the project properties to be able to use IvyDE.
> Exception message: failed to load settings from file:/C:/ivy/settings/ivysettings.xml: impossible to define new type: class not found: fm.last.ivy.plugins.svnresolver.SvnResolver in [] nor Ivy classloader

Because everything works fine when I'm using Ivy in Ant, I get the impression that my problem is in using Ivy with IvyDE and Eclipse.  Do I need to install the ivysvnresolver for eclipse in some way?  How would I do this?

Thanks,
--Jeff