If you leave the line default 0 as it is, your computer will boot with the kernel specified in the first boot stanza, i.e. with /boot/vmlinuz on the first partition of your first hard drive. Now, vmlinuz isn't the name of the kernel itself; it's a symbolic link to the last kernel installed - in your case vmlinuz-3.2.18-pclos2.pae - regardless of the order of the other stanzas.
So if you want to boot vmlinuz-3.2.18-pclos2.bfs instead, you have to change "default 0" to "default 5" as Just17 suggested. Or change the default in PCC.