The presence of Δ2-3 somatic transposase to Muller5-B X chromosome carrying five target P-elements causes pupal lethality, with or without heat shock P{S-UP2} can repress some of the lethality. Combination of P{S-UP2} and P{A-UP2} can repress pupal lethality, repression is induced or enhanced by heat shock. Combination of P{S-MP2} and P{S-UP2}, and P{S-BP2} and P{S-UP2} can repress pupal lethality slightly better than the single construct. P{S-UP2} fails to repress gonadal dysgenesis, either through a maternal effect or through a combination of zygotic and maternal effects, with or without heat shock. P{S-UP2} cannot repress sn^w mutability in the male germline or the somatic instability of sn^w (males have patches of weak sn, extreme sn and wild-type bristles) with or without heat shock. P{S-UP2} has no effect on the expression of the Ecol\lacZ gene of P{lacZ}sn^unspecified or P{lacZ}vas^unspecified.