Interesting George's balance problem has not been addressed. You did mention a prior stroke. Are you a type II diabetic. Loss of sensation or numbness, tingling in the feet. Any medical conditions that impact balance or equilibrium. I would suggest a visit to a good ENT physician or local Physical Therapy clinic that specialies in balance disorders. Advancing age does have it's pitfalls but rule out all the easy stuff before you become a permanent fixture in the spectator section.