Mobile Ad hoc NETworks (MANETs) are networks that do not require pre-configuration. Nodes in MANETs are arbitrarily connected with wireless links. Detecting and handling link/node failures is a challenging issue in MANETs. Many solutions have been proposed. However, only a few of them can be directly used at the application layer. Conferencing in MANETs includes a set of ?killer? applications, such as audio/video conferencing, gaming and distance-learning. Signaling is a critical component of conferencing. It handles conference session?s initiation, modification and termination. We have recently proposed a cluster-based signaling architecture for conferencing in MANETs. However the architecture does not address the unintentional departures of participants from the conference caused by link and/or node failures. This paper aims at tackling this issue. A novel session recovery mechanism is proposed. It is based on the well known concept of heartbeat. We modeled and partially validated the recovery formalism using Promela/SPIN.