[Koha] perl version with 3.4.5

Hi, I'm in the middle of my first Koha install. I'm running on CentOS 5.7 with perl 5.8.8. The Koha INSTALL file says 'You need to have a server running perl 5.8.8 or later', but 'make test' is failing due to perl 5.10-isms (eg C4/Search.pm line 497 'unless ( $data ~~ @used_datas )'. I'm on a server being used for other things and really don't want to try using a non-package-managed perl. Are the 5.10-isms few and far between, in which case I can probably patch round them, or would I be better regressing to an older version? If so, which is the most recent version I can use without perl 5.10 dependencies? Thanks Graham