UPDATE: After some digging around, it seems that the problem wasn't where I was placing the file, as it was in the correct location (~/var/mobile/Media/Documents). The problem was that I was using SendFile v0.37 on my 1.1.3 iPhone. I found SendFile v0.40-113 not in Installer but on Erica Sadun's site (
http://ericasadun.com/ftp/Applications/SendFile), downloaded it, installed through SSH using Transmit and voila, my docs now show up in SendFile.
Any reason why the version of SendFile in Installer hasn't been updated to the latest version?
cheers,
e