There is an outstanding issue with a conflict between the version of Guava and Java 7u51 that is being worked on the moment, see
Thanks for spotting that, Graham!
@Carlos: the error indeed looks like JCLOUDS-427. Are you running on 7u51? If so, can you try on an older version of Java for the time being? Or see [1] for more options.
Regards ap [1] http://apache.markmail.org/thread/637ayb6d6uz36bam
