'97 accord ac leaks
 

I've fixed a few ac systems but this one is a bit more trouble.

Condensor to receiver pipe had a corrosion hole at the clamp, bought a new
replacement from Honda. Recharged, high side valve didn't shut when I took
the hoses off. Replaced with a new valve core from a standard repair kit,
recharged, sniffer indicates leak at high side valve. Looks like gas is not
leaking through the core but around it. Do I need special honda valve cores,
or different o-rings?

Also seemed to be some leaking at the receiver end of the new pipe, which
was supplied with new o-rings.

Are these common problems? Any help appreciated.