Yes, unfortunately. My LC9s (not a Pro, BTW) came with one USA magazine. Before my holster got here I had already purchased two more magazines, and I'd heard about some problems with the USA ones so I bought Italian ones. As soon as I started carrying the LC9s I was experiencing "uncommanded" mag releases in the IWB holster. I trimmed the holster around the mag release button and the problem went away...or so I thought. I guess I'd also switched the "in the gun" mag to one of the Italian ones. A couple of weeks ago it started releasing in the holster, again. It took me a bit to realize that it was after I'd rotated my mags and, sure enough, the USA one was back in the gun for carry.
Just this weekend I bought two more Italian magazines at Cabela's and haven't had any problem with either of them.
So, for me the USA mag releases in the holster, usually when I twist to get in and out of the car but sometimes even just sitting in my office chair. I usually hear it click, even. None of the four Italian made mags do that. Over the weekend I examined them under strong light and a magnifying glass and the USA mag appears to have been stamped with dull tooling or something. The Italian mags all have very crisp edges that almost appear under cut. I found that if I push the mag release button towards the rear and begin pressing it in, the USA mag will release visibly sooner than any of the four Italian mags. I'm planning on taking a file to the release notch in the USA one to see if I can undercut it and make it stay in the gun. I'm not too worried about ruining it, because I refuse to knowingly have unreliable equipment...
I have
not, however, had the "drop under recoil" problem that some have reported with the USA mags. I've got a couple hundred rounds through the gun, about evenly divided between the USA mag and the first two Italian mags, and about 1/2 of them standard pressure and 1/2 +P, and have had no "firing-line" failures with any of them.
John