I'm a little late replying to this... however it is worth mentioning that some firewire devices do not like to be hot plugged. To be safe, your equipment should always be powered off before plugging/unplugging a firewire device. I was burned this way too. I unplugged my MOTU Ultralite while both it and the computer were on. No matter what I did afterwards, I could never get the computer to see the firewire device... I also tried plugging it into my laptop: that meant something in the MOTU itself had been shorted from unplugging it.

sounds like you roached the FW controller on the 1884... though frankly i thought that was more of a problem with plugging not unplugging.... afraid it's time to see the doctor.... BTW i recently saw where tascam has some fix for a few FW problems unfortunately they arent software fixes...