Certain Pages Redirect?

[Brookreed]

My site is nearly done, but there's one big problem that, no matter how much I search the forums or stare at the codes, I do not understand. Certain pages will not work, and redirect to the index page.

I kept a list as I worked, see for yourself:
Daycare
All links on Messages page
All links on search page
Shops (when you click on the arrow to enter the shop, it redirects)
Links to member pages (cannot view a member's profile), nor own.
Change Password
Change Email
View and Manage FriendList
More Profile Settings
Change Other Settings
Custom Pages created in the ACP will not load to their proper pages/view/pageurl page.
Levelup link
Get BBCode Link
Manage an Adoptable

Everything redirects to the homepage. Basically, any default link on the main part of the page doesn't work.

It's a bit frustrating, because, you know, these are necessary links. Users can't send messages, or levelup adoptables, or even enter a shop. Does it have something to do with the main php files? I know that there is no daycare.php file...

So...help? I barely know how to PHP code, but I sort of understand how the files work. I just need help figuring out why this is happening.

I'm using FireFox and IE as browsers to test it, using Mys 1.3.3, and using x10hosting as a host.