I have had no problem with placeholders using DBI and DBD::Sybase, but I use the Sybase client libraries (libct), not FreeTDS. (I am currently using DBD::Sybase v. 0.91 and DBI version 1.16 with perl5.6.1 on both Compaq OSF and RedHat linux, but this has worked with older versions as well, and I suspect it still works with the newer versions of DBI and DBD).

In short, I would suspect FreeTDS...

--JAS