We perform two-dimensional numerical calculations of the tidal interac
tion between the companion star and the disc around the primary in a c
ataclysmic variable system with parameters appropriate for the eclipsi
ng dwarf nova binary IP Peg. We show that a spiral shock pattern is in
deed obtained. We find, however, that it is impossible to reproduce th
e two-armed spiral that has been recently observed in IP Peg for reali
stic discs.