disklabel wd1 (virtual disk mapped to phys HDD on MS Virtual PC) just displays one partition - "c".
At the same time i remember, that on VMWare disklabel for virtual disk mapped to phys HDD displays two partitions - "c" and "i" and i've mounted it without problems like that - mount /dev/wd1i /mnt/win (it works without -t vfat parameter!)

p.s. the order of parameters to "mount" differs between linux and openbsd. e.g. - -t parameter MUST precede nodes in BSD.