The firewire (i.LINK) port on Lite-On set-top DVD+HDD recorders only works for streaming video from a firewire video source (e.g. DV camcorder) to the DVD recorder. Unfortunately, it will not stream out video or provide access to the DVD recorder's HDD or DVD drive from a PC.
If the warranty is already up and you need to transfer a large number of recordings from its HDD to a PC, at your own risk, one option would be to open up the DVD recorder, take out its hard disk and install it in a desktop PC to access its content. If you do this, do not write, delete, defrag, run chkdsk, etc. on the HDD while it is connected to the PC, as the Lite-On uses a modified FAT32 file system. Unfortunately, from what I've read around, its HDD is not recognised by most USB->IDE adapters.