max, it's a long shot, but you could try holding the cards with the formulae on them above eye level (is it left or right?) to acces your visual resources. I have been told that helps in learning, but I have never used it myself.
Since I last posted, I have been checking up on stuff about O'Brien, and, although his methods are pretty much the same as others, I found a site that raved about him and his now out of print book, so he may be the better of the three after all. Here's a link:
http://www.happychild.org.uk/acc/tpr/gtm/0009domo.htm
