I know I'm late to the discussion party here but I've been busy lately with RL stuff.
I hate, hate, hate, hate these nicknames with a fiery, burning passion. It's not only these, but most pet names in general that tick me off to no end.

Where I work, older people and the elderly are our main customer base and I get each one of these names sometimes multiple times a day; I just grin and bear it, but inside all I want to do is tell them "This is my name, it's on my tag, read it, it's not difficult."
But I'm not allowed to say things like that at my job. Most of you are right though that the elderly don't usually care what gender you are when it comes to pet names, I think it's kind of a generational thing. I rarely ever get these sort of names from someone under 40. It's pretty obvious to a lot of people what my physical sex is, partly thanks to my terribly betraying voice.

I guess what ticks me more than anything is when I -know- that some people are using these names simply because of my appearance. I've only gotten 'Sir' a few times; I thought my head was going to swell like a hot air balloon even after that man realized his 'mistake' later on.