Pin lock kegging questions

Hey all,
So I recently started brewing beer again and have decided to get my kegging going. I have pin lock kegs courtesy of my step-dad and Coca-Cola Co. My questions are as follows:
1) the posts thread onto the keg easily when there are no o-rings in place, but after placing the o-rings under the gas in and liquid out dip sticks, the posts don't thread as well. I did set it all up and charge it with CO2 and it has held pressure without leaks, I'm just wondering if this is normal?
2) Do the poppet valve for the Firestone-type pin lock kegs have o-rings on them? If so, does anybody know of where to replace just the o-ring and not the entire poppet?
3) I bought "universal" poppet valves from Midwest supply, and they don't seem to reach all the way to the top of the posts. Anybody use these with pin lock kegs?

I think that's it for now, thanks in advance for any and all help!

Jason

1) Need more information about how it "sticks". If its holding pressure, it should be fine. If you put a seal thats too large on the posts, they'll thread down in a wierd way, but they should still seal properly. Basically the seals are probably binding on the actual post itself. Use some keg lube and the problem should go away.

2) Yes they have seals. Not sure where you get them though. I just have a bucket of spares I swap out on. If someone finds them, PM me pls.

3) I think those are made for ball locks, but I'm not sure. I haven't used universal fittings because I have lots of spares.