EDIT: I fixed it by not installing the NDK Development stuff. I don't know what it is, or what it does, but it fixed my problem.
I'm on Windows 64-bit, using Eclipse Helios, and trying to install the latest Android SDK. So far, I've been able to download and install the SDK Manager and successfully ran through its stuff.
The trouble comes in when I try to install inside of Eclipse (Help -> Install New Software). Every time I try to install using either the URL address (http://developer.android.com/sdk/installing/installing-adt.html) or the .zip file I get this error:
An error occurred while collecting items to be installed
session context was:(profile=SDKProfile, > phase=org.eclipse.equinox.internal.p2.engine.phases.Collect, operand=, action=).
Comparison method violates its general contract!
Comparison method violates its general contract!
The internet doesn't seem to have any answers that I can find. Thanks!