4 days before the release of 10.10.10, but I hope this stays relevant after the next release...
If you want to get MP3s from the Amazon store you need to use their MP3 downloader, which has been built for Ubuntu 9.04 and isn't explicitly future compatible. The app wants libboost-*1.34.0, whereas 10.04 comes with 1.40.
To get it working on 10.04 I followed the instructions here:
wget https://launchpadlibrarian.net/26959932/libboost-signals1.34.1_1.34.1-16ubuntu1_i386.deb https://launchpadlibrarian.net/26959936/libboost-thread1.34.1_1.34.1-16ubuntu1_i386.deb https://launchpadlibrarian.net/26959922/libboost-iostreams1.34.1_1.34.1-16ubuntu1_i386.deb https://launchpadlibrarian.net/26959918/libboost-filesystem1.34.1_1.34.1-16ubuntu1_i386.deb https://launchpadlibrarian.net/26959916/libboost-date-time1.34.1_1.34.1-16ubuntu1_i386.deb https://launchpadlibrarian.net/26959928/libboost-regex1.34.1_1.34.1-16ubuntu1_i386.deb https://launchpadlibrarian.net/34165098/libicu40_4.0.1-2ubuntu2_i386.deb
sudo dpkg -i *.deb
rm -r old_boost
This installs the old libboost as required by the app. I then apt-get installed libglademm-2.4-1c2a and the downloader worked fine. Which is good, because then I could listen to the very enjoyable Ninja Tune label sampler. Well worth the effort.