Pure pub/sub behavior in Reverse Ajax

I have an expectation from Reverse AJAX that may not be compatible with DWR's implementation. I was wondering if someone can clear this up, or if I am just seeing an outstanding bug:
http://www.nabble.com/Jetty-and-Reverse-Ajax-Performance-tf3366524.html#a9394546

I am testing the clock example that uses comet to send a ScriptBuffer to a client every second. I am also using Jetty in embedded mode on the server and FF 2.0.0.3 on the client. The call to dwr.engine._poll() is occuring just fine when my page loads. (I am seeing a call to _poll() timeout every 10 successive calls or so, as others have reported.)

My question is whether I should expect regular DWR calls to return their results on the _poll() connection, or do these calls keep their own connection open until the server has satisfied their request?

Thanks,
Jim