NewRelic error when run under Glassfish 2.1

NewRelic worked fine when running under jruby/mongrel and seemed to work fine running under jruby/glassfish prelude (I had other issues with prelude so I bailed on it), but when I ran under jruby/glassfish 2.1 I would intermittently, but often, see the following error:

[#|2009-01-30T15:49:24.804+0000|SEVERE|sun-appserver2.1|javax.enterprise.system.container.web|_ThreadID=19;_ThreadName=httpSSLWorkerThread-10002-0;_RequestID=6ab78a8d-a609-4fc9-9e85-878b4e041d95;|WebModule[]Exception caught
/home/steve/glassfish/domains/domain1/applications/j2ee-modules/20090126184409/WEB-INF/vendor/plugins/newrelic_rpm/lib/new_relic/agent/instrumentation/dispatcher_instrumentation.rb:70:in `dispatcher_finish': NilClass can't be coerced into Float (TypeError)
from /home/steve/glassfish/domains/domain1/applications/j2ee-modules/20090126184409/WEB-INF/vendor/plugins/newrelic_rpm/lib/new_relic/agent/instrumentation/dispatcher_instrumentation.rb:41:in `dispatcher_finish'
from /home/steve/glassfish/domains/domain1/applications/j2ee-modules/20090126184409/WEB-INF/vendor/plugins/newrelic_rpm/lib/new_relic/agent/instrumentation/dispatcher_instrumentation.rb:49:in `dispatch_newrelic'
from /home/steve/glassfish/domains/domain1/generated/jsp/j2ee-modules/20090126184409/loader/rack/adapter/rails.rb:37:in `serve_rails'
from /home/steve/glassfish/domains/domain1/generated/jsp/j2ee-modules/20090126184409/loader/rack/adapter/rails.rb:44:in `call'
from /home/steve/glassfish/domains/domain1/generated/jsp/j2ee-modules/20090126184409/loader/jruby/rack/rails.rb:145:in `call'
from /home/steve/glassfish/domains/domain1/generated/jsp/j2ee-modules/20090126184409/loader/rack/handler/servlet.rb:17:in `call'
from :1
...internal jruby stack elided...
from #<class:01x51e7b969>.dispatcher_finish(/home/steve/glassfish/domains/domain1/applications/j2ee-modules/20090126184409/WEB-INF/vendor/plugins/newrelic_rpm/lib/new_relic/agent/instrumentation/dispatcher_instrumentation.rb:41)
from NewRelic::DispatcherInstrumentation.dispatcher_finish(/home/steve/glassfish/domains/domain1/applications/j2ee-modules/20090126184409/WEB-INF/vendor/plugins/newrelic_rpm/lib/new_relic/agent/instrumentation/dispatcher_instrumentation.rb:49)
from NewRelic::DispatcherInstrumentation.dispatch_newrelic(/home/steve/glassfish/domains/domain1/generated/jsp/j2ee-modules/20090126184409/loader/rack/adapter/rails.rb:37)
from Rack::Adapter::Rails.serve_rails(/home/steve/glassfish/domains/domain1/generated/jsp/j2ee-modules/20090126184409/loader/rack/adapter/rails.rb:44)
from Rack::Adapter::Rails.call(/home/steve/glassfish/domains/domain1/generated/jsp/j2ee-modules/20090126184409/loader/jruby/rack/rails.rb:145)
from JRuby::Rack::RailsSetup.call(/home/steve/glassfish/domains/domain1/generated/jsp/j2ee-modules/20090126184409/loader/rack/handler/servlet.rb:17)
from Rack::Handler::Servlet.call(:1)
from (unknown).(unknown)(:1)
|#]

My fix was just to remove NewRelic, but please let me know when this is sorted out so I can put it back. Thanks!

rails: 2.2.2
jruby: 1.2 (pre-pre-release, ask charlie nutter for a copy from the nightlies)
glashfish: 2.1
java: 1.6</class:01x51e7b969>