I don't have any problems with my D90. I just feel like it's getting a bit "long in the tooth" and am worried about the longevity of this particular camera. I have very few shutter actuations -- about 11,434 according to myshuttercount.com (I believe is the website). I've heard that the D90 can get up to 100,000 but not sure how realistic that is. I can't afford to keep the D90 and buy the D7000. So, if I were to upgrade, I'd have to sell the D90.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ “When words become unclear, I shall focus with photographs. When images become inadequate, I shall be content with silence.” ― Ansel Adams