2003 Passat GLX will not start

Here is my problem with a 2003 GLX wagon with 4 Motion. On Monday of this week, I try to start my Passat. The engine just cranks (just like it did the day before when it started right up) but will not start. There is no engine warning lights. Battery is strong. I try turning it over 3 times (~ 5 - 10 Seconds each) and it will not start. I wait about 3 hours and try again and it will not start. It just cranks but will not turn over. I did not crank it so much that I would consider it to be flooded. I have it towed to the dealer. After 2 days (of back log) they get it to start up by just essentially cranking it over (They do tell me they had it connected to a battery booster). They also tell me when it started it was running like it only had 4 cylinders (rough idle). They take it out for a test drive and it seems after 'warm up' to run fine. It was like in the old carborator (sp?) days. The next day they test drive and run it thru engine diags and find nothing. It starts up fine. Does anyone have any ideas? Here is a couple of other items. When the car would not start on Monday, it was parked in our garage. About a year ago, the passat was very hard to start (sitting in the garage). Once I got it to startup after it cranked for a while, it idled very rough then achieved a normal smooth idle and everything else seemed fine. We took it into the dealer and they did say they found a diag code that indicated a misfire had ocurred 1 time. Again, if anyone has an idea I would appreciate seeing your response. Thanks!

You had no dash lights or warning lights like oil pressure or battery light when it wouldn't start? Or are you saying the check engine light did't cycle on?

The dash info icons/lights appeared just like it always had (on a normal start) prior to trying to start it when it would not start. I did look to see if the mil light was on which it wasn't. When you turned the key to the on position (before engaging the starter) quite a few of the dash lights (engine check, etc) would come on; but I do not think there was anything out of the normal. Thanks for replying so quickly. Any other ideas?

It's pretty key info whether the check engine light cycles on when you first turn the key on & try to start (under a no-start condition). If not, suspect the ECM power supply relay.

Sounds like an Ignition coil problem.

When the car is running and warm.. mist some water over the ignition coil at he front of the engine (the middle big engine cover must be off)
It the car starts runnin crappy- Replace the coil