I’ve gotten hit on by my fair share of men, so I’d say I’m at least “attractive” enough to answer the question. 
The only time I’ve ever noticed a woman getting uncomfortable/bitchy around me is when I’m talking to her date/boyfriend/husband…I bartend for a living, so it’s my job to talk to people, but a lot of women assume that I’m after Their Man. Even if he’s twenty/thirty years my senior. Perhaps especially, b/c I’m younger than she is and I’ve talked to people for so long now in this job that I have a very friendly, casual “jive” that can, I suppose, be misinterpreted if you’re paranoid.
And it’s got nothing to do with how much I try to butter her up, either…some women are just very insecure, and no matter how hard I try to make them feel comfortable, they just don’t like it.
Beyond that, no. I’ve got several very attractive friends, too, and we’re all on an equal footing with each other and we don’t play that “I’m the pretty princess/you’re the ugly stepsister” routine. Please. We’re all gonna get old and saggy one day and we’ll need old and saggy friends to keep us laughing about it.
I think the only real problem facing an attractive/pretty woman is not being taken seriously; people assume you don’t know much, and that you skate by on your youth and beauty. If I go into a camera/computer/whatever shop, I usually get the “And how can I help the pretty stupid little woman” salesman who thinks I’m a sitting duck. Even when it’s obvious I know more than he does.
But this isn’t an earth-shattering problem and it would be stupid to take it seriously and bitch about it all the time…women who do that are just looking for sympathy and, as Drastic mentioned, more compliments. Any woman walking around going, “God, it just sucks to be this beautiful! Life is so hard!” is the kind of woman who, consciously or not, makes it clear to everyone that she really thinks she’s hot stuff.
And nobody likes that, so yes, the response may be catty, but she usually starts it with her “look at me I’m beautiful” attitude.