Namur: I solved that freeze at my end (on Win7 64) by changig the compaytibility settings on the shortcut from Win98 to Win XPSP2. At least one more user reported this also worked for him. Have you tried it ?
This along with the new executable posted by support helped me get past the second guards! I hope it doesn't freeze again... I'll report if it does. Thanks!
Update: It froze again a couple minutes past that point, but since I've switched to WinXP SP3 in the compatibility tab and disabled "Threaded Optimization" in the NVidia control panel for the game's executable (Atlantis.exe) I haven't had the problem so far.