I say that but I know of some Russian parishes where the old babushkas will smack you for standing in the wrong place.
I can assure you no one would say a word to you about it in any of the parishes I frequent. Number one they would appreciate you being respectful and number two you would almost certainly be asked if you were Roman Catholic. I will say even for a Catholic the amount of movement and things going on during the liturgy can be either overwhelming or disconcerting. You genuflecting would for the most part go unnoticed.
DISCLAIMER: Catholic Answers has turned over the archive to Catholic-Questions.org and no longer owns, manages, or moderates the forums. For additional apologetics resources please visit www.catholic.com.