Reg squeaking noises. Normal?

Ok. I have. Huma reg in my impact and when I take a shot it would squeak for 1-2 second. I know it's due to the high pressure going into the reg chamber. But I have shoot many guns with regs and they do not squeak. All you hear is the pop of the muzzle blast. It's very annoying to hear your gun go boom, then follow by a squeak. I took the reg out and clean it from any dust or lube and just install it back without lube or anything. The squeak goes away. But after a few days it would do it again. Is this normal or what? What cause this noises and how would I make it go away permanently?
 
Is it possible that a lubricant could be migrating from the bottle adapter fitting to the reg? The fact that the squeak goes away when you clean and dry the reg is suggestive of something getting to it after a few firing cycles. Might try replacing the O rings on the reg body. I'm not familiar with the Huma reg in this application, so I'm just guessing. I have a Huma in my Royale 400, and I've never heard a squeak.