To get DBD::mysql version do:
perl -MDBD::mysql -le 'print $DBD::mysql::VERSION;'
To get DBI versions do:
perl -MDBI -le 'print $DBI::VERSION;'
selectrow_array is built into each DBD so if you upgrade DBI you need to rebuild DBD::mysql. Recent versions of DBI (1.605 - http://search.cpan.org/~timb/DBI-1.607/Changes) contain some fixes for selectrow_array but I don't think ones that affect what you are doing. However, I'm guessing you have upgraded DBI and not rebuilt DBD::mysql as at present I cannot think of any other reason for this.