SSL 3.0 "Page cannot be displayed"

Yesterday I solved a weird problem where one of the machines in my network couldn't display any SSL 3.0 encrypted pages. IE would tell me "Page cannot be displayed", Firefox would pop up a window saying something like "Received invalid message header". I found the reason for this very surprising: in my router the DMZ was stet to the machines IP address and that somehow kept SSL 3.0 from working properly on that machine. If anyone can give me a technical explanation for this I would be very happy.