Migrate database from 5.1 to 5.5

Hello,

I would like to migrate a database from a blog to a new sql server and i have the choice between 5.1 or 5.5 in the version, i’m using 5.1 but i wonder if it is better to use the new one or if there are things that will not work if i upload the database to this version of the server, can you please let me know which one i should choose?

Thanks a lot!