Is my FW-series interface compatible with Mac OS X 10.6 Snow Leopard?
The discontinued FW-1884, FW-1082 and FW-1804 are only compatible with 32-bit Snow Leopard operations.
Are there Windows 7 (64-bit) drivers for my device?
Yes, 64-bit compatible drivers (V1.80) are available for download here.
http://tascam.com/product/fw-1884/downloads/ <<< click here.
I have the same Tascam mixer/interface. Try booting your Mac in 32 bit mode. Hold down the 3 and 2 keys when starting up. That will put it in 32 bit mode. Then try your mixer. Mine works and I have the same OS that you have. I'm using an iMac. Just an FYI - It looks like upgrading to Mountain Lion you will no longer be able to boot up in 32 bit mode. If you do, you're mixer/interface will no longer work. Good luck!
I'm still struggling with my FW-1884 and my Mac Pro. Originally the device and the computer would not recognize each other. Eventually I found out the problem was within the Fire Wire buses. The FW-1448 doesn't like converting from Fire Wire 800 to Fire Wire 400. After installing a Fire Wire 400 port on my Mac Pro I've found the Tascam will work around 50% of the time.