I had a problem on my PC, that didn't allow me to access any ShareCG page, except the ad for the green contest.  With help from David Heller, we figured out my problem.  My PC was set to the wrong date.  It would create the cookie as of one date, then triy to read it as of the following date.  As a result, the cookie always expired before it could be used.  Check to see if the time and date on your PC is correct.  This is just a wild guess, but it costs nothing to check.

-David