Openldap stable to use with freeradius

["Roberto Pioli" <roberto.pioli@csp.it>]

I want to use openldap with a radius server ( Freeradius-- 
www.freeradius.org ) for authorization and accounting of a wireless hot
spot.
What is the more stable version of openldap that I can use?.The last one or
it is better to use onother one?

Thanks

Roberto Pioli