After an evening of trying to work out why my D-Link wireless router had stopped connecting to AOL the helpful chaps at D-Link asked whether I had just upgraded iTunes.
I had upgraded iTunes a day or so previously and miraculously after uninstalling iTunes and reseting the router it worked fine. Apparently they've been quite busy on the D-Link techical line as a result of the latest iTunes becoming available!
The chap at D-Link talked me through some changes to my router settings and advised that I could now download iTunes again without it causing a problem.
As you will have noted, I am not profficient with the technical aspects of wireless routers but thought I would post my experience here in case it helped anyone out.