What type of tubing are you using and what is the pressure on your regulator?
I am using an Up Aqua in-line atomizer and had to crank it up to 30 lbs when it was new to get it to atomize (now for some reason it now works at 20lbs-I probably was impatient and didn't wait 5 or 10 minutes).
At 30 lbs, I found that everything was leaking C02 and my hoses popped off, so I happen to have a roll of 1/8" ice maker vinyl tubing and it worked great with no leaks and stayed on, it even fits nicely on the Up Aqua barbed fitting with the lock down nut. Its very stiff and a little hard to get it on the barbed fittings on the regulator and bubble counter, so I heat it with a lighter and it goes right on-with no leaks.
Its very durable. If you need to remove it, you need to take a sharp razor knife and cut a section off the side-don't slice it perpendicular to the barb or you may cut the plastic barb or put a scratch-channel in a brass barb.
I don't think the diffuser being clogged will mean much since the regulator pressure shouldn't continue to build (unless you have a creeping regulator, which is another story).
Unless you have really high pressure, your tubing is probably the culprit. When I have used silicone tubing, you can feel it puff up and expand as the pressure grows-making the internal diameter expand which makes it easier to pop off the barbed fitting.