This Unicode version will not give full search functions in any pre-2011 nuvi, sorry. In other respects it will work though. See:
[Only registered and activated users can see links. Click Here To Register...] and
[Only registered and activated users can see links. Click Here To Register...]. The correct map for your 310 is the non-unicode NT which is will not be updated any more than twice a year now. Current map is 2014.40:
[Only registered and activated users can see links. Click Here To Register...]. We're hoping the next update is imminent.