Well, my latest report is that I can still access the 825 login page since D-Link support and I made the changes. The significant one is me removing the D-Link Network Monitor. BTW, you can just click the X in the gadget to close it and remove it from the Desktop. It'll still be available in the Gadget's list. I know Microsoft, recently, has dropped/changed support for gadgets as the myriad of gadgets are no longer available.
Note that I had no issues with the DIR-655 while running the gadget on 3 different computers. I'll report back tomorrow and see if the page is still accessible. If it is, then I'll reenable the gadget on one computer and see if after that the 825 setup UI becomes inaccessible after some time.
BTW, you can use URL Snooper if you want to see what request commands are sent to the router. You can copy them and post them in a browser so you can see the XML results. I'm wondering if getting so many of these requests is not "compatible" with the 825 or is introducing a bug that D-Link may not even be aware of right now. In my case, whatever the "ping" frequency of these commands is, it was multiplied by 3 since I was running the gadget on 3 computers.