Comparing my Blitz rating of 900 to my Tactics Trainer rating in the 1400's, that speaks to a huge discrepancy.
My best guess for that gap has been best explained to me by a very strong chess.com player, hicetnunc. I simply don't know the 950-1200 problems well enough, and there's a certain percentage that I don't know at all. That's what the Chess Tactics for Students book is for, covering all of the basic tactics that I need to know within a certain rating range.
He gave me pretty much the same advice as Dan Heisman, and that is to do problems rated between 950-1200, both random and thematic (repetition), with the goal of solving them in about 5 seconds, so that I can spot them instantly in my games.
Once I have that homework assignment completed, I would expect my Blitz rating to shoot upwards towards 1200, since I will be seeing so many more tactics during my 10 0 blitz games. That's the plan.
I reset my Tactics Trainer rating, zoomed upward, and am hanging in there at a new high - the 1400's!
I like to reset my tactics trainer history everytime before a training session. For some psychological reason, it is more motivating to start that way, then to keep my history.
At Chess Tempo, my history is saved, and I also do custom problems there, like remove the defender only problems, pin problems, etc. The software has a built in repetition feature, which has you repeat the puzzles that you missed, not right away, but at a certain time interval.
I use Tactics Trainer as a test, just to see if I am improving, not so much for pattern recognition, as there is no repetition feature. With that said, I do see reoccurring tactical themes, and that helps.
Chess Tactics for Students by John A. Bain has been a big help. Dan Heisman highly recommends this book, saying that it is the best book for covering most, maybe all of the kinds of tactics problems in the 800 - 1200 range, which he advises every chess player to nail down. He think's that this way of learning tactics, by really knowing all of the 800-1200 problems, solving them in 5 seconds, is the fastest way to improve one's tactical chess, and chess rating.