Icampbell,
I had a similar experience with a Canon FC-8M (8MB) CF card. I'm pretty sure it wasn't the card because the same ard worked for the v3.51 (and later the v4.0 update).
I posted it in this thread:
http://forum.eventide.com/cs/forums/t/5586.aspx
In short, I couldn't update directly to v4.0 but it worked when I did v3.51 first.
bt