Are you sure you didn't develop a mechanical problem with the extractor?
+1. Did switching to different ammo subsequently solve the problem, or did you just give up at that point?
How did the rims of the ejected brass look? How about the empty casing that didn't eject? A bad extractor will often leave deep scratches or take little nibbles out of the rim as the extractor jumps over it.
I suggest inspecting the extractor. It should have a sharp edge and corners, and should not be clogged with powder residue and brass shavings. Try prying it outwards with your finger; I'm not terribly familiar with the P95, but on most automatic pistols, moving the extractor with your finger is difficult but possible.