The stability of a hot particle annulus in a mirror cell at arbitrary drift reversal is analyzed by using a cylindrical model with embedded currents that simulate the role of field line curvature in actual mirror experiments. New effects are included by taking into account the Landau damping arising from the spread of hot particle drift velocities. It is found that the ‘‘precessional layer’’ mode is destabilized near the pressure gradient value at which drift reversal is achieved. Its growth rate is proportional toN−4, whereN−2is a coupling constant &ggr;2MHD/ &ohgr;˜2&kgr;[&ohgr;˜&kgr;is the curvature frequency, &ggr;MHDis the typical magnetohydrodynamic (MHD) growth rate]. In addition the unstable interaction of the precessional layer mode with surface waves that can propagate below and above the ion‐cyclotron frequency is described. Below the ion‐cyclotron frequency the surface wave resembles the Alfve´n wave, while above the ion‐cyclotron frequency the surface wave resembles a whistler wave.