The solution your provided, Sprogget, just doesn't make sense. I really don't see what wireless encryption has to do with a blocked port.
A true conundrum! But, the bottom line is it works. And that's what matters!
PS: I have never been happy with Belkin products in the past and steer a wide path around them. If you get a chance you might check out Netgear products. From my own personal experience they seem to have very nice products with a support team which is very, well, supportive!