I am using MusicCabinet 0.7.22 in Chrome. If I click a link that causes a last.fm page to open (recommended artist name, for example) and then I click another internal link (such as a navigation button along the top, or an artist name from my local directory) a new tab will open with that content instead or navigating away from the last.fm page in the center frame.
Signing out and back in does solve the problem, until I view another page from last.fm.