This issue seems to be more problematic on Chrome than Firefox, but sometimes, when moving from a location on the timeline, the map location does not shift.
For example:
In
http://timemapper.okfnlabs.org/arielsegal/camden1
When moving from
2005
309-311 Mechanic St., Camden, NJ
to
2004
919 S. 9th St., Camden, NJ
the map location and label does not shift. I checked the coordinates in my Google Spreadsheet and they appear to be accurate.