hmmmmm, not going to say that Im an electrical genieus or anything, but here is my experience with timers.....

cheap timer problems:
plug in ballast, bulb dosent always fire
plug in ballast, bulb fires, bulb soon goes out
plug in ballast, bulb fires, bulb flickers alot, not as bright as it should be
plug in ballast, bulb fires, bulb randomly goes off and on

When I changed to expensive timers I never have had any of these problems runiing them on the same power source...

So if you ask me, timers can make a difference in some way
mabey you found a cheap digital timer that did the trick for you, I didnt....
I found that the dial timers work fine too, but dont use them...