I have produced a (hopefully simple to use) program that will scan your network for DLNA-enabled Humax devices, and allow you to easily download them to another device on your network.
It also has a facility to decrypt files that are encrypted via the .hmt file. So it works like a dream on my HDR1800.
If you want to give it a try, you will find it, together with some instructions for use at admin edit: link removed
It is very much a work in progress, so if you have any problems trying to use it, email me using the address on the website.
I hope people find this useful.