I'm so glad you liked it ^.^ As for your problem, I've tried to find it myself, playing it both in English and Spanish, and asked my regular readers to look out for it, but so far nobody else has seen it so I'm not sure what's going wrong in your copy of the game.
All I can tell you that the point where the CG is meant to unlock is on the line right after the CG, when Kyou is standing in the corridor.