After a lot of testing, I just can say that the "trick" described in the first message works great. I'm using it for all communication between the server and the Swing client, even for JMS ObjectMessages, and the performance problems are gone.
This for GlassFish 2.1 and 2.1.1, I haven't had a chance to test the application in GF3.
PS. I marked this question answered, as the manual serialization "trick" solved the performance problems.
Regards,
jrico
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