Hello Nick and Mary Pat,
Oddly I seem to be having the same problem that you had with my Imacon Flextight Precision II scanner (that blinking green light issue and a "scanner not found" error message). Mine was originally a SCSI scanner that I converted to firewire using a RATOC firewire adapter. It was working fine that way when I last used it but like you I hadn't used it in several months and during that time I foolishly upgraded the OS from (I think) 10.2.3 to 10.4.11. I'm wondering if you got yours working and if so how you did it.
Here's some background:
I'm running it on a G4 (with the firewire connection card from RATOC (firmware 1.33) using flexcolor 4.1.1. I think when we converted it I tried a SCSI card first but got nowhere with it and ended up with the firewire converter (it plugs right into the back of the flextight and it needs it's own power as well).
I checked with RATOC and I think I have properly upgraded drivers and utilities there.
I installed 10.2 again on another partition and tried Flexcolor 3.66, 4.01, 4.02, 4.03, 4.04, 4.5.2, 4.8.5 (on both versions of OSX). Both vers. of OSX see the firewire converter according to the system profiler.
Now I'm thinking about trying to install classic and going at it again. This scanner is a valuable resource for me and this process is maddening - any hints would be appreciated - Bob