The branch is here: https://svn.jboss.org/repos/labs/labs/jbosstm/branches/JBOSSTS_4_2_3_GA_CP
Thanks for the patch. Unfortunately JBTM 4.2.3 is in critical bug fix only mode so we won't be able to add this to that branch. Also in later revisions of the software we are now handling these exception types and logging them to disk.
Hopefully as you upgrade, that will still fulfil your customers requirements.
Thanks for your answer and for the info on later revisions, that's good to know.