Can't get valve stem keepers out. HELP PLS!

OK. I did everything by the book, but it ain't workin'. Got the compressed air in the cylinder (that works a lot better than I though it would ) Got the V/C off, got the spring compressed with the overhead style valve spring compressor. Now everything I read tells me the valve should sit still, and once the spring and top hat are compressed a bit the keepers should be so loos that you can remove them with a magnet. I tried both the intake and the exhaust valves, and no luck. The spring, the top hat, and the keepers just all stick together. I even tried tapping the top hat around the edges to loosen them, but the just won't budge. HELP!!!