This card, using a TI chipset, has always been annoying.
My son saw a lot of mysterious firewire issues with devices connected through the card, though we were never able to pin down the culprit.
While advertised as compatible with a wide range of machines and systems, it is a 5 volt only PCI card, limiting it to older hardware.
At least on my example of the card, F5U503 Rev.S-3, there is no internal power connector, limiting the useful capacity to one bus powered device, e.g. iPod or 2.5" hard disk, but not both at once. This is not an issue if you plan to use 3.5" or 5" firewire drives which have their own power supplies.
The failure to support deep sleep is the most infuriating aspect of the card. Macs are competent and reliable sleepers, going months before rebooting. The Belkin card prevents deep sleep, something I only learned on the Belkin support site long after I bought the card.
Whether for PC or Mac, I'll choose more carefully next time.