tedster - 2:32 am on Jun 26, 2012 (gmt 0)
Whatever happened with the title displayed for your page (Google does keep tweaking their title display rules) I say your loss in rankings is NOT because of the change in the displayed title. Ranking is the main calculation and it includes your URL's actual title element. Then the display in the SERPs is determined by another algorithm or set of rules.
What happens if your search terms include that final word? The title display algorithm should include that word and be compressed somewhere else.