...I would suggest that you get an up to date version. You can find this at www.squeakvm.org/unix. The files at this site are maintained by the creator of the unix VM for Squeak, and they are always the most stable and up-to-date available.
I can vouch for the quality of this work. I myself run FreeBSD. The precompiled binary is for FreeBSD-4, which is on the brink of being desupported by the FreeBSD core team. It doesn't run on the current release of FreeBSD 6.1. However, the UNIX sources are well-enough maintained that they compile out of the box without error on FreeBSD 6.1, and run just fine.
Mike O'Brien