AmabayFox v 1.3.20120310, and possibly earlier versions, leaves zombie compartments after the page has closed.
Steps to Reproduce:
1) after installing addon navigate to amazon.com and select a common product
(e.g. http://www.amazon.com/gp/product/0439023521/ref=s9_pop_gw_g14_ir04?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=center-4&pf_rd_r=1VNNKEY7G2BAJF2EWX60&pf_rd_t=101&pf_rd_p=490157971&pf_rd_i=507846 - The hunger games)
2) see the icon change to bell to indicate matches available for product
3) click on icon to launch comparison page (optional?)
4) close down Amazon and comparison tabs
5) go to about:memory?verbose and click minimize memory usage button a few times
6) see compartment still listed for Amazon page
zombie compartment fixed.