I know I should be able to find the answer to this, but I have spent about 6 hours on this board searching and reading, and I've kinda given up. I have a Nuvi56LM on firmware 3.2. I'm trying to install the Europe maps. I have downloaded the map in full, and downloaded only the parts I need (UK). I take the file, drop it into gimgunlock, copy to an SD card, and every time I get "cannot unlock maps" on my screen. Followed my "maps are corrupt and cannot be used"

Can someone please help me out.