I have never heard any mention of fake K240 Mk II's. What makes you believe they are fake? I have a real pair and the original box if there are any comparisons you need.
(Fake Sony V6's/7506's, and Audio Technica M50's yes, but not these ones.)
[Added:] Found this:
http://www.akg.com/forum/index.php?topic=2202.0;wap2
On mine, the AKG on the top of the band is solid, not outlined like the older model. And I know mine are a genuine pair. Also, mine have a little sticker on the inside of the headband, Made in China. No longer Austria for this model. I got mine from an authorized dealer last fall or so, and they sound 90-95% like the older K240 Sextetts.
Edited by Kevin Brown - 3/10/11 at 10:01am