Many thanks for getting back to me ksenks.
I'm now running 3170. If I try to connect more than two devices a sheet pops up saying that "All USB ports are currently being used." The development hardware that I'm using has three USB connections and a serial connection, so I have all three USBs and a KeySpan USB to serial connection plugged into a Belkin hub which is then connected to my desktop iMac. I'm afraid I'm not allowed to reveal the exact nature of the development hardware.
Using Apple System Profiler I can see that this is a USB 1 hub. Does this mean that the devices will only connect to the virtual USB 1 controller, and therefore there is still a limit of two devices?
I tried an experiment: I plugged one of the three USB connections direct to the iMac and can now connect all three, but not the KeySpan (I'm out of ports). So my theory is probably right: USB 2 devices need to be on a USB 2 hub to get round the two device limit.
If this is indeed the restriction then perhaps the error messages need to be a bit clearer, and the USB 1 and USB 2 devices separated (or indicated) in the user interface.
So the next step is to buy a USB 2 hub and try that. I'll report back.
Last edited: Feb 26, 2007