I've found that in the Najdorf and many other Black openings, Rybka still considers White better after I give Black an extra move. Take the following for example:

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Nxd4 Nf6
5. Nc3 a6 6. Bc4 e6

Now, I give Black the extra and useful move b5. White has gained no additional information since this was an important move anyway and after White moves the bishop to b3, Black will develop flexibly with Be7. White is just a full tempo down. The following position results:

White to move

Rybka 2.3.2a evaluates this as a normal advantage for White (~.15). Given that this line is considered close to equality without an extra move for Black, I expect Black to more than equalize here. This should be even more important because it is a fighting asymmetrical position where tempi matter. Although, Rybka tends to actually evaluate the value of a tempo higher in symmetrical positions since unlike the Sicilian, the armies are in contact already. Thus, Black is usually just considered better after an extra move in the Lopez. Anyway, why doesn't Rybka recognize that Black is at least equal here? Is its initial evaluation so wrong?