On Wed, 23 Apr 2008, Paul Goyette wrote:
I think this is what you're looking for: PS2M (SYN0302) at acpi0 not configured
[...]
I _have_ "pms0 at pckbc0" in my config file, and the dmesg shows a "pckbc0 at acpi0" exists. So it would seem that this particular device is not being recognized as a PS2Mouse. And the PS2M line in the dmesg occurs at exactly the place where you'd expect it to find the mouse (ie, right after it finds "pckbd0 at pckbc0").
As Valeriy said, you need to add the SYN0302 ID to the list of supported devices in sys/dev/acpi/pckbc_acpi.c
Cheers, Jared