I think I fixed it. When I messed around with the options a little, I checked "Increase Permgen Size" and started up a superflat grassy world, and it put me in it nice and fine. I don't know what was wrong with it before, but at least it works now.
Title: Shutting down internal server on world creation
Version: 1_0_3
OS: Windows 7
Java Version: Java Version 6
Description of Problem:
Whenever I try to create a world it's working nice until right when it's going to put me in it. Then it freezes for a minute and says "Shutting down internal server". Then it doesn't do anything but stay on that screen, and then stops responding. I'm slightly new to tekkit, so I don't know much on how to fix it.
Error Messages:
Shutting down internal server...
Error Log: