Possible to download firmware from running embedded install?

[hcsteve]

I have an Alix 2d3 installed in a remote location running 2.0-RELEASE.  I'm using this device as a SIP proxy (running siproxd) for close to 100 phones and it works beautifully.  I've been trying to replicate this setup for another site and I'm having some strange problems on my new setup.  I think there may have been some modifications to the remote unit aside from just the config, so I'd like to try to duplicate it as closely as possible.  Is it possible to download a complete copy of the remote site's CF card for use locally?  I tried the following command but after mounting the resulting image, some of the directories are unreadable.

ssh root@[remote ip] dd if=/dev/ad0 bs=16k > pfsense_running.img

It's my understanding that the CF card is normally mounted read-only so there shouldn't be any issue with file contents changing during the read, but I could be missing something here.