tedster - 6:13 am on Feb 3, 2012 (gmt 0)
The issues people have been reporting come from frequent or widespread title changes. An occasional title tweak can make good sense as you say - especially if there is some modification of the content accompanying it.
The key is not to become a "robot" about any particular SEO technique - your toolbox should be very well equipped and not merely focused on title tags and anchor text. Those are very sensitive areas.