spatial solr classnotfoundexception

I am installing the jteam solr plugin for spatial search.  I dropped the spatial-solr-1.0-RC3.jar into the example/lib directory and got the following error:

Jan 6, 2010 9:30:53 PM org.apache.solr.core.SolrCore initListeners
INFO: Added SolrEventListener: org.apache.solr.core.QuerySenderListener{queries=
[{q=solr rocks,start=0,rows=10}, {q=static firstSearcher warming query from solr
config.xml}]}
Jan 6, 2010 9:30:53 PM org.apache.solr.request.XSLTResponseWriter init
INFO: xsltCacheLifetimeSeconds=5
Jan 6, 2010 9:30:53 PM org.apache.solr.servlet.SolrDispatchFilter init
SEVERE: Could not start SOLR. Check solr/home property
java.lang.NoClassDefFoundError: org/apache/solr/search/QParserPlugin
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:616)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
        at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
        at java.net.URLClassLoader.access$000(URLClassLoader.java:56)
        at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:303)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
        at org.mortbay.jetty.webapp.WebAppClassLoader.loadClass(WebAppClassLoader.java:375)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:296)
        at java.net.FactoryURLClassLoader.loadClass(URLClassLoader.java:592)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:248)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:316)
        at java.lang.Class.forName0(Native Method)
        at java.lang.Class.forName(Class.java:247)
        at org.apache.solr.core.SolrResourceLoader.findClass(SolrResourceLoader.java:357)

Obviously, doing that broke something. I suspect that it had something to do with the classloader that I used, so I moved my jar (spatial-solr-1.0-RC3.jar) to the example/work/Jetty_0_0_0_0_8983_solr.war__solr__k1kf17/solr/WEB-INF/lib directory, and all is well!