Thanks for the response...hmmm...sounds like something like that - I normally wear thorlo socks, I just tried wearing an extra pair of cheapo athletic socks over the thorlos for more cushioning - same thing happened. I even tried playing at about 50% of the exertion I normally put into my movement.
How do I tell when my shoes need replacing? My shoes look ok (sole hasn't worn through yet), but I've been wearing this pair for over 5 months.
I'll probably scale back the amount of tennis I'm playing for a few weeks and see if that helps.