One airbrush problem solved?

Something I've been noticing about the airbrush the last few weeks, is a problem with paint atomization. That's just a fancy word for the airflow blowing the paint from the needle into the air in really small particles.

I've had my share of issues with the airbrush so far, but this was new. 

It wasn't tip-dry because I had it almost all the time and cleaning the tip seemed not to help. 

It wasn't a bad paint consistency, because without the compressor on, the paint just drips out if I retract the needle. I sometimes had bubbles forming in the paintcup, almost as if there's a turbulence in front of the needle pushing air in instead of away from the tip.

When the brush IS blowing out paint, it's too wet and runny, indicating the paint is too thin, not too thick (because I've been working under the assumption the paint is too thick). So what's left that could be causing this?

I've come to the point where I've decided to buy a new airbrush, more expensive. It's just a matter of deciding which. I'm currently favouring the Badger Renegade Velocity, but I haven't yet made up my mind.

As if this decision triggered something, the following happened ...

While trying again to put some primer on the Enterprise, some paint accidentally made it on the front of the airbrush, where the needle cap is screwed into the nozzle cap. To my surprise, the paint started bubbling in a place where no bubbles should be forming.

I took my camera and shot the following video :

Even with the cap screwed on really hard, air still escapes, lowering the pressure in the front considerably and modifying the airflow into something I've already deemed unworkable.

After just a tiny bit of vaseline on the entire thread of the screw, a repeat test showed no bubbles whatsoever and a quick test with random paint showed a VAST improvement in paintflow.