I present a variation on Osaki ’ s tidal-thermal-instability model for SU UMa behavior .
I suggest that in systems with the lowest mass ratios , the angular-momentum dissipation in an eccentric disk is unable to sustain the disk on the hot side of the thermal instability .
This decoupling of the tidal and thermal instabilities in systems with q \lesssim 0.07 allows a better explanation of the ‘ echo ’ outbursts of EG Cnc and the short supercycles of RZ LMi and DI UMa .
The idea might also apply to the soft X-ray transients .