Trying to open a Review on our PMUG site David Passell got only a dark grey screen. He describes the problem and solution here. He was running Safari Browser (version 4.0.5) running under Snow Leopard on his Mac Mini. He had previously tried to open the Review with Firefox and "with a minor annoyance it displayed very well." The solution he found at this link. He had to set Safari to run in 32 bit mode, and he found that by default, the Safari browser runs in 64 bit mode, which is incompatible with Adobe Reader.