The new version of ObjectStreamClass introduced in recent merlin builds does
not declare an explicit serialVersionUID, which makes it impossible to
serialize ObjectStreamClass.class between 1.4 and earlier VMs.

(1.3.1-b12)
$ serialver java.io.ObjectStreamClass
java.io.ObjectStreamClass: static final long serialVersionUID = -6120832682080437368L;

(1.4-b46)
$ serialver java.io.ObjectStreamClass
java.io.ObjectStreamClass: static final long serialVersionUID = -6539648802376000715L;