How do you get shadows to suck less?

[Thulghor]

So after doing a bit of troubleshooting trying to figure out what my last bit of little lag was coming from, I discovered it was shadows. It doesn't happen all the time, but when it does happen, it is noticeable. Seems to happen when I'm auto attacking a mob. I'll just suddenly lag like crazy, then it will go away. Also, while quite a few of the shadows look just fine, some are very off. So much, that I can sometimes see them go through walls and stuff, or they are stretched really really really long. Changing the shadow clip plane distance does nothing for performance or this issue.

I have more than enough system juice to make this happen, and I've also done all the tricks (affinity, memory settings, compatibility, moving out of program files, setting frame cap to 60, etc.). The rest of the time, the game runs like a champion. I don't run WinEQ2 after it started doing bizarre crazy stuff.

So, is there any way to make shadows not suck so bad?

My system specs are as follows (just because I know someone is going to ask):

OS: Windows 7 64-bit Professional
CPU: Intel Core 2 9650 Extreme Edition
Memory: 8 Gigs of 1066 Mhz Corsair XMS2 Dominator RAM at CL4
Graphics: XFX Radeon HD 5970 Black Edition
Secondary Graphics: Evga Geforce 8800 GTX
Sound: Soundblaster X-Fi Fatal1ty Extreme Gamer
Motherboard: MSI P45 Neo 2

I can also post my EQclient.ini if need be. I'm sure I have some settings off or something. Like I said, rest of the time, runs like a platinum god.

Any help would be much appreciated, thank you.