SD
its just the wireless that has the problem.
Packet analyser sees packets sent but no returns to local pings, it does see returns from internet pings.
Rpi does not respond to pings from the local network on wireless, but does on wired
Arp table has the wireless router address which is designated as a gateway but nothing else (tried adding routes but at extreme edge of knowledge on that)
tried not to have wireless and wired at the same time to prevent the confusion you allude to.
1 step forward, I eventually managed to make the local PC a wireless hotspot and make a wireless connection to it from the pi, lo and behold i can ping whatever successfully including the router. so my theory at the moment is power related in that some how the pi scans for wireless routers on high power gets the dhcp then reduces power which is insufficient for a ping. (signal strength to the router is around 30-40%) as the hotspot is feet away signal strength is 99% and ping works as expected. well thats the best I can come up with at the moment.
Rick (appologise to rans6 for hijacking his post a bit but something might be relevent)