If you have spark on all four cylinders and the engine is turning over nicely, then it's time to look elsehwere for your problem.
Is the bike firing at all? Does it sound like it's even trying to start? Is gas getting into the cylinders? Thats easy enough to check, the plugs will be damp after a bit of cranking.
Spark on the plugs should come in a nice rythm, there should be no 'missed beats', and all four plugs should be sparking (not at the same time). What is the condition of the spark? Is it a narrow rather sickly looking spark, or is it a nice fat blue spark? If it's not a nice fat blue one, go get yourself some new plugs.
From my understanding, most dead Igniters will result in a no-spark condition. Some, though, will still spark. However, the ones that do still spark do not spark in a nice rythm and do not produce spark on all four cylinders, more than likely just on two (there are two 'signal' lines from the Igniter, one to each coil).