This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
I am not sure, but JtaTransactionManager is the parent class of WebsphereUowTransactionManager in Spring. Maybe because you are using something more specific to Websphere, it can't get that value anymore.
Wish I could tell you more.
subject: Transaction name null if WebsphereUowTransactionManager is configured