As a newcomer and having experienced this I read up on a few posts about these "deviations", you are not alone. I'd say it is a fairly hot topic!
I think it is to represent that in real life a nicely executed shot can still go awry (but awry doesn't necessarily mean way, way, way, off, I think that is the argument).
About heavy winds in every game, try clearing your cache, both temp. internet files (browser) and adobe flash player:
http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager07.html