When trying to use UserTransaction in client code I keep getting the following exception:

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javax.transaction.SystemException: java.lang.RuntimeException: UT factory lookup failed: javax.naming.CommunicationException: Receive timed out [Root exception is java.net.SocketTimeoutException: Receive timed out]
at org.jboss.tm.usertx.client.ClientUserTransaction.begin(ClientUserTransaction.java:107)
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client's code follows:

UserTransaction utx = (UserTransaction)CMObjectLocator.getInstance().getInitialContext("sushi.private").lookup("java:/UserTransaction");

utx.begin(); // throws said exception


What's possibly wrong?

Thx for any help,
Marc

CMObjectLocator is just a wrapper and actually gives me the server's initialContext.