Why is the @ bookmark so far behind?

[Sean Farley]

$ hg log -r stable
changeset:   18325:777084ac8416
branch:      stable
bookmark:    crew-stable
tag:         crew/stable
user:        Tim Henigan <tim.henigan at gmail.com>
date:        Thu Nov 29 08:44:54 2012 -0500
summary:     dirstate: remove obsolete comment from setbranch

$ hg log -r @
changeset:   18072:e853d27956fb
bookmark:    @
parent:      18069:c64e646af81e
parent:      18071:f94ead934067
user:        Matt Mackall <mpm at selenic.com>
date:        Wed Nov 28 18:08:51 2012 -0600
summary:     merge with stable