Help with embedded packet capture

I'm testing the ability to perform packet captures remotely. In my test, I'm only getting one side of the conversation. My test setup is a pair of 4500-X in VSS with dual downlinks in a port-channel to a 4507 with a desktop(192.168.55.107) plugged in. Test was a ping to the desktop from a router upstream. Here is my configuration.

ip access-list extended TestCapture permit ip any host 192.168.55.107 permit ip host 192.168.55.107 any monitor capture BuffCapture interface Port-channel5 both monitor capture BuffCapture access-list TestCapture monitor capture BuffCapture buffer size 10 monitor capture BuffCapture start