If you watch and listen very closely to Bulma in the episode during the Adroid Saga where the Z-Fighters have just let Adroid 20 (Dr. Gero) escape from their grasp, she clearly states that it was him that they were fighting and she knew where his lab was because she had read an article in one of dads magazines. Yet, after Piccolo relayed the message that Trunks told Goku to everyone else, she wanted to use the dragonballs to find his hideout? It makes you wonder though, if the Bulma of the past knew this type of information, why didn't the Bulma of the future relay it all to Trunks???