This is a response to volume 3, Tomás Card Number 5 ("Thanks, John")...
I have consulted with Robert on this matter and we both agree that you need a gadget called a Powerport to make your Thunderscan work with your Plus.
The problem is that the Plus, unlike the 512, does not provide a 5 volt power source through the printer or modem ports. The thunderscan needs that power and the only socket on the Plus which can provide it is the external drive port.
The solution is an adapter called the Power Port which Thunderware now bundles with all new scanners. It's a little box that plugs into the external drive port with a cable which plugs into the printer port. You, in turn, plug your Thunderscan box into the powerport. I was able to pick up mine from a computer store for about thirty dollars. If you can't find one, you might try calling Thunderware and see what they advise.
As for the initialization problem, that should NOT be happening! I can only suggest that you replace both your system and finder files (of course you will have to transfer your old desk accessories and fonts into the new system). What version are you running under? The latest release is version 6.02. If you have any trouble upgrading let me know and I'll see what I can do.