AEBS: Bad Packets Unrecovered TCP Retransmits NV and NV+

If you still have your old router, you could try putting it back in the network, temporarily replacing the AE. I did something like this when I replaced my old Netgear FS105 with a D-Link DGS-2205 switch and as long as I only had my old NV+, all was good. When I added an NVX, I could copy files to the NVX but not retrieve them. After doing a direct connection (using the same S.P. Hardy link you posted) I determined that the NVX was fine, so there was another suspect afoot. Replacing the new switch by temporarily reverting to my old slow FS105 solved all my problems (except for speed) while I awaited my new Netgear GS108 switch.

You might also temporarily disconnect your wife's computer and VOIP phone when it would be the least inconvenient for her. Throughout your testing, you have not commented on them, and while not directly in your sub-network, they are attached to the AE and there could be something in them that is affecting it. At this point all possibilities should be examined.