Should joints leak until warmed up?

I have a couple joints (manifold to UP, manifold to manifold just before UP) that I can feel exhaust coming out of when I take off all the shields and idle. Before the car warms up, I get a leak at about 10 psi (you can clearly hear it), then once warm, I can go right up to 18 psi or so no problem. The connections look like they're tighter at the two bolts, then gap ever so slightly at the mid points...the multi layer metal gaskets seem to fill up that "void" once the car warms up. Is that normal for it to leak before it warms up? I imagine in the dead of winter this may take quite a while. If a gasket may need to be replaced (they all look intact), is it normal to have to replace gaskets every 2 or 3 years?

Leaks have been a bit frustrating to me...my oxygen sensor backs out all the time...I finally drilled a small hole on the edge and safety wired it. Ah the joys of NNA engines (non non-aspirated ;-)

What kind of uppipe do you have? The flanges could possibly be uneven.

It took me a few trys(o.k like half a dozen) to get it leak free (cobb up and down pipe ) I kept on trying to resuse gaskets and working only 1 joint at a time.

Use all new gaskets and loosen all the joints including the turbo connections, then slowly tighten everything back up........Good luck!