A cease-fire on charges of sexual behavior has been called in the divorce trial of San Leandro millionaire Preston Jones and | his wife, Janet, and testimony vesterdav and todav in MarinW «rSuperior Court reverted to fi*, nancial matters.The truce, apparently initiated bv Jones, owner of Prescolite , Corp. and seven other companies. came only after his blonde. 42-year-old wife challenged Jones’ sexual potency, disclosed he persisted in undressing in the privacy of closets, and claimed he chased other women, jEnough, said Jones yesterday, | expressing concern over the tor- j rid publicity’s effect on their son. Preston, 10. A mutual agreement against sexual allegations was reached in the chambers of Judge Samuel W. Gardiner.Testimony resumed at 10 a m. today after D. J. Blattner, an appraiser-engineer with a Milwaukee, Wis., firm, estimated the Jones’ companies have had average net earnings of $282,633 a year for the past five years, and that Jones’ salary has been about $46,000 a year. Mrs. Jones, who resides at 16 Marina Way in San Rafael, is asking $2,300 a month alimony and child support, and community property.