Looking at the stack trace it appears to be an issue with corba serialization in the container. I found this bug,
https://glassfish.dev.java.net/issues/show_bug.cgi?id=2693 in which the stack looks almost identical to yours.
The only way that I think TopLink could be involved is that TopLink is weaving your code, and potentially so is corba. You can try turning off weaving to see if that 'solves' your problem. (Note: I am not confidant that this will work, but I notice that the corba stack may be doing some weaving of it's own.)
The persistence unit property is toplink.weaving. Setting it to false will turn off TopLink weaving.
<property name="toplink.weaving" value="false"/>
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