I am migrating from JSF 1.2 to 2.1 and upgraded RF to 4.3.5 along the way. I encountered a problem in every place where I use <a4j:ajax event="..." onbegin="onBegin()" oncomplete="onComplete()" />. onBegin() is called once. onComplete() however is called multiple times and I have no idea why. Has anyone seen something like that? What can cause that?