LOL...okay, here we go...
I understood that if a gate doesn't function properly anymore it is possible that the goa'uld add a second gate on the planet.
Daniel and Teal'c explained the antartica gate to Hammond in Solitudes this way. But I think it's more likely that the gate wasn't *not* working, but just covered under ice. (Because later it is working.)
It's possible the antartica gate was the one that malfunctioned (or rather was covered)...and that's why they put a second one on earth...in Egypt...
And yes, the gate connected with the DHD is the primary gate, but if my assumption that the antartica gate didn't work anymore/got covered is correct, then the egypt gate with the new DHD would have been the primary gate. And since the germans found the DHD and the russians confiscated it at the end of WWII we know that there *was* a DHD in egypt at one time.
I heard we will get to know which gate was the first one in season six...looking forward to that.
After the SGC gate (I'll call it alpha gate) crashed with Thor's ship the SGC used the antartica gate (beta gate)...so that's what I meant when I said it worked later...
The Russians found the alpha gate and put it to use with their DHD. I just wonder whatever happened to the antartica DHD...It seemed to work because when Sam tried to dial earth Daniel noticed slight tremors in the SGC. She just couldn't dial earth because earth was the point of origin. Why continue using the dial computer if they have a working DHD???
The gate they used to destroy the sun in Exodus was the gate on Vorash if I'm not mistaken...after they evacuated all the Tok'ra from the base they 'beamed' the gate to their mothership.
Does this make any sense??? LOL