"could be a check valve in one/some of the lifters isn't working"
Don, I'm not familiar with the lifter check valve. Is the valve an integrated part of the lifter, or is it a part that's separate from the lifter? I had a lot of clatter with the stock lifters, and recently had new ones installed. I had hoped that this would solve the cold clatter problem, but it didn't. If replacing the lifters doesn't help, how do we fix lifter bleed down?
Does bleed down cause the lifters to wear prematurely, or is it just a "normal" (HD's new favorite word) benign thing that comes with the 110? I'm trying to figure out which of the numerous engine noises I can safely ignore.

Dan
This may be a poor description Dan but I'll give it a try. Yes, we're talking about something that is a part of each lifter. Nothing separate. When oil pressure pumps up the lifter this makes the lifter fully expanded or solid (not meant to compare to an actual hard lifter). That expansion is what is correct for the length of the pushrods and rest of the system to both make the valves open correctly and to do that without clatter in the valve train.
If a lifter would bleed off when the oil pump is no longer supplying pressure then as the engine starts up there would be valve lash or free play in the valve train. The hydraulic check valve in a lifter is intended to keep the lifter pumped up (enough) or, to put it another way, to keep up from not draining back when there's no longer oil pressure supplied by the oil pump.
If that check valve isn't working the valve train will be noisy on first start up. This won't last long though. It'll take only seconds for the oil pump to repressurize the system. So if the noise you're concerned about lasts longer than that it's not a lifter that is unloading.
The only way to fix a lifter that is bleeding down is to replace that lifer. They're not a serviceable item. Having said that sometimes (rarely) you can solve the problem without extensive service. Use a little Seafoam before the next oil change or a can of Marvel Mystery Oil as part of the next change (though I'd recomment not run it a long time before changing again if you do the latter). Both might clean some bit of whatever is keeping the lifter sticky and get it behaving better again. Not a likely solution. But it is cheap and easy to try if it's actually a sticky lifter problem.