BeagleBoard Crosscompile Error

Hello, I'm college students in south Korea.
I am using Beagle Board for the project.
So I used manual of Beagle Board in homepage
But, I get Error in [Sysdev - Cross-compiling toolchain] chapter

I followed the order.

./configure --local
make install
./ct-ng help
./ct-ng arm-unknown-linux-uclibcgnueabi
./ct-ng menuconfig
./ct-ng build --------> I got Error

./ct-ng build

[INFO ] Performing some trivial sanity checks
[INFO ] Build started 20120103.200735
[INFO ] Building environment variables
[EXTRA] Preparing working directories
[EXTRA] Installing user-supplied crosstool-NG configuration
[EXTRA] =====================================================
[EXTRA] Dumping internal crosstool-NG configuration
[EXTRA] Building a toolchain for:
[EXTRA] build = i686-pc-linux-gnu
[EXTRA] host = i686-pc-linux-gnu
[EXTRA] target = arm-unknown-linux-uclibcgnueabi
[EXTRA] Dumping internal crosstool-NG configuration: done in 0.12s
(at 00:02)
[INFO ] =====================================================
[INFO ] Retrieving needed toolchain components' tarballs
[EXTRA] Retrieving 'gdb-7.1'
[ERROR] Could not retrieve 'gdb-7.1'.
[02:45] / make: *** [build] Error 1

I would like to know why the error occurred.
What is the solution?