2004 Other Fiat Models over reving

Hi there, my fiat idea petrol seem's to over rev when i change gear for a seond or to before dieing down any ideas. can you help me!!

i've shoved a clip on youtube to help



http://www.youtube.com/browse?&ytsession=cSHLDHCCP_4ElK_Wmnvpdrkxv7TzQoDkg_dSKLnx1wkxWWRoUP5k63MrHIA-2sYx3xat9tAjuseWKG4R_PbhQOMv6vkSHF4XxgHJvEH--wsECV9auuozLBRkT3c0NsADIs-AD1mD1w1z68YIPzmMzCRrNUWk7O4lTKxVO3tploKtoMiBMudTlG6pW2cKVkOP7WPyZO0r10Nly15NuTU5rrqn-Z_ZHo3xj9NMl8TE67Uq4FspK8ixdfO4hf6BedykFhmlr67hiSxf6-RdnaMKog