*Points to own signature* xD
I see nothing wrong with cross gender roleplay, since all it is, is collaborative storytelling. Writers out in the real world don't (usually) make every character in their books the same gender, or even their main characters the same as their own gender. It's really no big deal, as Ali said.
While I have seen some people get weirded out by cross gender roleplayers, it's usually because they see Rp as a kind of branch-off of real life, and picking a mate for your character also seems like you're also selecting a mate for yourself, or your account.
Which, as a general rule of Rp, it simply isn't. Cross gender role-playing, again, is really just storytelling, like every other character. It's just not one of those things that need to be taken so heavily. ^^'