Why cant i get in to defeat Wild Sunbird, I dont understand why I cant get in, I am lvl 24.
If you were given the quest to fight the Sunbird, and it won't let you in the doorway or gate, it is a bug.
When you get to that area, just press down and HOLD the forward arrow key until it lets you in. It takes a minute or two, but eventually you can get it. If that doesn't work, send an e-mail to email@example.com and explain the problem to them.
Also, you might want to go to the Halston's Lab section on these Message Boards. They have a thread started called "Have a Bug?..." where you can report any bugs you find, like this one. :-D