What MSG said - it's very common. Can you give us some more info about your bass, what strings you are using, and what styles you are playing? Another part of the equation is technique. For me, the relationship to the bass is like an intimate relationship with another person: it takes a while to get to know your partner and find the groove of your relationship to (him/her/it). From a technique standpoint, to a certain degree you have to play slightly differently (especially with the RH) to get the sound you're hearing in your head out of each bass. With some it's easy, with others not so much. Strings and setup can help, but a part of it will be an adjustment in technique as well. Fill us in on your bass and setup details when you get a minute.