serialization exception

Hi,

we are getting the following exception while running a transform with xalan.

Has anyone seen this problem before?  It happens even with Xalan 2.6.0

The class ExtensionNamespacesManager is not serializable, it looks like
this class is held by
StylesheetRoot, but should only be there if the stylesheet uses
extensions.  We are using java extensions.

So is this a limitation of some sort?

[ERROR]: store(..): Exception
java.io.NotSerializableException:
org.apache.xalan.extensions.ExtensionNamespacesManager
        at
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1054)
        at
java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1330)
        at
java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1302)
        at
java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1245)
        at
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1052)
        at
java.io.ObjectOutputStream.writeArray(ObjectOutputStream.java:1224)
        at
java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1050)
        at
java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:278)
        at