Non-Optimized Media Error

I am using Final Cut Pro HD on a kind of @#$%& G4 and OSX Panther to edit a feature film project that was shot on a DVX-100a in advanced mode and 16:9. If that's not crazy enough for you I have another confession to make, I am using about 6 Lacie hard drives all daisy-chained together through a Firewire 400 card. I realize that this is an uncommon compilation of bad hardware and confusing technology, but astonishingly enough it has been working more or less fine for about the past 3 months. At least the only problems have arisen out of FCPHD's limitations with 23.98 footage (removing the advanced pulldown and synching the audio), not out of any hardware limitations.

But in the last few days that has inexplicably changed and I am in a major jam. Final Cut has always occasionally warned us that all of our 23.98 footage is not optimized and we should re-capture it all or use the media manager to copy it all to a new hard drive. However we've never had any problems with our footage, we've been editing day and night for the last couple months, so we just ignored the warning more or less and kept working. But now suddenly all of the footage has gone out of synch, and when we double click on a clip to watch it in the viewer, it plays extremely choppy and acts like the footage truly is not optimized for final cut pro. We are getting the Non-Optimized media warning every time we turn on our system now as well, where before we only got it once every couple weeks or so. The footage plays choppy even when I start a new project and re-import the footage, and it happens with all our past Auto-Saves going back a week or so to before this problem arose, so it is retro-active apparently.

I've tried trashing Prefs, re-writing permissions, and most other general things that normally fix our problems, but none of it has made a bit of difference. Is it that our daisy-chained drives have reached their firewire 400 limit, or is there some other problem causing this?

And furthermore how do I fix it, I've had a friend suggest buying a TeraByte RAID Drive and copying all the footage over to it, and seeing if the footage works again off of the RAID, but it's a pretty large investment for us to buy one of those just on a hunch... will copying over to a RAID Drive really make this footage work, or do we actually have to start over from scratch? All of this footage was working fine a week ago, and I'm almost 100% positive nothing new has been installed and no preferences or settings have changed, we haven't even captured anything new in the past month. Please Help, any advice would be greatly appreciated.

Ty