Lechwe:

Just to throw something else in the mix -- double-check your saddle angle. It should be pretty close to level (take a clipboard, slap it on top of your saddle, and throw a level on top of that, assuming your bike is on level ground). If it is angled down too much, say more than 5 degress declination, that will definitely shift your weight forward to your hands even if your fit is perfect otherwise. A lot of folks tilt their saddle down to alleviate perineal pressure . . . the real problem is that they need a different saddle, not a ridiculous saddle angle. FYI, I run a 1.3% declination angle on my saddle (I think level to 3% is a good target range).