2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/10734I review several problems which arise when one tries to apply the standard dwarf nova instability model to outbursts of soft X-ray transients.11 pages, 2 EPS figures, Latex, uses paspconf.sty Invited review at the IAU Colloquium 163: "Accretion phenomena and Related Outflows", 15-19 July 1996, Port Douglas, Australia, Eds. D. Wickramasinghe, L. Ferrario and G. Bicknell, ASP Conf. SeriesAstrophysicstext