i'm currently running oacs 4.6.2 beta and 4.6.2 final on mac osx 10.2.5 with dec2002 dev tools. i've been following the instructions of markd, and after some initial troubles am now quite happy...
one big culprit is the .tcl file you use for starting up the oacs application. try using a very minimal one and see if that makes any difference.
also remember to restart the nsd-process after mounting applications and regularily vacuuming your db!