Graphics problemsFollow

I just started FFXI on PC after switching from PS2 and I'm experiencing a TON of problems... 1. I can see the sun through walls and it blinks really fast. 2. People tend to disappear and reappear (PC and NPC) and it seems to take a long time to load each person up one by one even though this computer breezes through Battlefield two on high everything settings. 3. I can't use AH counters. When i can finally get one targetted it always says the target is too far away even though I'm right next to it. I CAN get into the AH by talking to the people though, just not the counters.

Anyone have any solutions? XD Thanks in advance.