The ehcache bundle (org.apache.servicemix.bundles.ehcache-2.5.1_1.jar) was updated after the release. As described here [1], the bundle manifest had a typo. This was later corrected and the bundle was reissued.

[1] http://svn.apache.org/viewvc/servicemix/smx4/bundles/trunk/ehcache-2.5.1/pom.xml?view=log