Big news, everyone: GRE Prep Club has just introduced a new feature: verified GRE scores! Now we can finally tell who is telling the truth about their scores.
To verify your GRE scores through the ETS website, go to "My Profile / Applicant Profile / GMAT Information (should say "GRE Information) / Add GRE score" and follow the instructions. You will be asked for the login and password to your ETS account in order to verify (although the process is secure, I suggest changing your password immediately afterward, just in case).
Once you've verified your score, the grey question mark to the right of your scores should turn to a green checkmark (see the lower left-hand side of my profile for an example, or see the screenshot below).
By the way, I'm also a GMAT tutor--in fact, I have about 3 times as many GMAT students as I do GRE students--and GMAT Club verifies GRE scores as well:
Best of luck on the GRE and beyond,
Brian