Well the Telstra says Chinese / English; I bet this means there are different input methods and such in the firmware, which would account for it's size difference.
Pay attention to how your fonts look, it's not uncommon on a "chinese" phone (I.e. a phone designed to support double-byte characters natively before single-byte, like English) to use a slightly smaller, skinnier font as the default. I've never loaded one of these on a BlackBerry though, so I'm interested to know what you find.
EDIT: I should have said "firmware" not phone in the above paragraph