I'm trying to use firstbits to generate a shortened address and it just complains that the address is not in the chain even though I have made transactions with it. Blockchain.info has already generated a firstbits address so it should be working. However, when I pasted the blockchain.info address into firstbits, I got a completely different address to the one that was supposed to be shortened. I have no idea what's going on but this can't be good for firstbits, right?
For example, this address:12roGRp1DuvzZF97JkryNpbpdRDwm4DmWh https://blockchain.info/address/12roGRp1DuvzZF97JkryNpbpdRDwm4DmWh
has firstbits 12rog but if you type that into firstbits, I get a completely different address out: 12RogVscnRvknEEptc3UwH6mxmuBzYH6fz https://blockchain.info/address/12RogVscnRvknEEptc3UwH6mxmuBzYH6fz
and if I shorten that one, I get 12rog out which is weird.
Are blockchain.info and firstbits operating on different chains? Am I completely misunderstanding how firstbits works or is something actually going wrong here?