Later version of library don't satisfy dependency

(I had to say "don't" because "doesn't" didn't fit in the subject line)

I'm trying to install the Amazon MP3 downloader.

They're a bit behind -- they have a downloader available for "Ubuntu 9.04"

I downloaded it and tried to install -- but it says there's a dependency that can't be resolved:

Dependency is not satisfiable: libboost-filesystem1.34.1

I installed libboost (and a bunch of other sub-items in the Boost library) using the Ubuntu Software Center, but the version of Libboost is higher now than it was in April of 2009 (surprise!)

Why doesn't a NEWER version satisfy the dependency? Is there a way to override it?

Stuck...

Thanks in advance for any help.

Matthew