I have this exact same issue. I was running the same version of Glassfish (GlassFish v3 (build 74.2)). I downloaded v3.0.1 b19 yesterday and it did not help with the problem. I can run the app client successfully using java web start on one machine with 1.6.0_13 but it fails on different machines with 1.6.0_18 and 1.6.0_19.
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