Cracked coils are not the only cause....
The problem lies in the standard ecu, retarding timing and over fueling when the AFM detects too much air flow (ie: when you start to run more boost).
With good coils you will experience a flat spot. With fatigued coils you will experience misfire.
Gapping your plugs down helps.
The best solution is to replace your ECU with a programmable ECU, and get yourself some new coils.
If you cant afford to do both of those, then a SAFC will also help (if not fix the problem) by leaning out your fuel mixtures.
And covering the cracks on your coils, and cleaning the contact points is a good substitute for new coils (given the internals of the coils are still good - which they almost always are).
I took the latter path...
almost 4 years ago I gapped my plugs down to 0.8mm and the misfire turned into a flat spot.
2- 3 years ago I got a SAFC fitted and tuned for a 12:1 A/F ratio and the car drove like a dream. No flat spot, no misfire, just got better and better all the way to redline.
1 year ago my misfire issues came back - so I put araldite on the coils - car was driving better than ever...
6 months ago, a missfire occured at 3 - 4 rpm - I cleaned the contact points on my coils with WD-40, and the car was, and still is driving like new....
So have a search on ALL of these points, they were coverd years ago, and I'm guessing the newer forum members dont pick them up in their searches b/c the threads are so old now, so try searching in ascending order (ie: older threads come up first)