I'm surprised that your Dell Inspiron notebook doesn't have an 1394 port at all. It's unfortunate. USB 2.0 has up to 480Mbps or 60MB/s bandwidth but it's hardly good for 16x DVD burning.
It's a common phenomenon for USB devices to be lost sometimes. I myself often experience it, but I also have IEEE 1394 cards and I can always connect the same DVD writers using PCI cards of onboard connectors. It's usually USB driver problem, on the software side that is.