Apt-Pinning: Installing libboost from Jaunty repository into Intrepid Ubuntu

Question

I'm trying to install libboost 1.38 in Ubuntu 8.10 using a Ubuntu 9.04 repository since it isn't avalable in any of the 8.10 repositories. I'm trying to use an Apt-pinning by adding the following lines of code:

/etc/apt/sources.list:
deb http://us.archive.ubuntu.com/ubuntu/ jaunty universe

/etc/apt/preferences (Which I had to create):
 Package: *libboost*
 Pin: release a=jaunty
 Pin-Priority: 900

Which gives me the following error when I try to open Synaptic:

E: Invalid record in the preferences file, no Package header
E: _cache->open() failed, please report.

Answer 1

There should be no leading space in /etc/apt/preferences entries.