Great! I think this will help us a lot. I'm guessing that this
exception is thrown from ParseUtil.java:110 while it is reading
the POST body from the request InputStream.
As these requests are delayed by 60 secs my next guess is that it
is waiting for data and times out. Is the SimpleFramework socket
possibly configured with a timeout of 60 secs? Could you configure
the Simple socket to another timeout value and try again?

Maybe you could also configure your SimpleReq->ServletReq adapter
to spy on the input stream and log what data is actually fetched
by DWR for the different requests, so we can see how much DWR is
actually fetching before giving up on the slow requests.

I'm also noting that the
 throw new ServerException
on line 110 isn't being logged, so we can't see the nested exception.

Joe: could we add logging of this exception?